DNA recovery and analysis from skeletal material in modern forensic contexts

Epigenetic age prediction using costal cartilage for the investigation of disaster victims and missing persons

The DNA intelligence tool, DNA methylation-based age prediction, can help identify disaster victims and suspects in criminal investigations. In this study, we developed a costal cartilage-based age prediction tool that uses massive parallel sequencing (MPS) of age-associated DNA methylation markers. Costal cartilage samples were obtained from 85 deceased Koreans, aged between 26 and 89 years. An MPS library was prepared using two rounds of multiplex polymerase chain reaction of nine genes (TMEM51, MIR29B2CHG, EDARADD, FHL2, TRIM59, ELOVL2, KLF14, ASPA, and PDE4C). The DNA methylation status of 45 CpG sites was determined and used to train an age prediction model via stepwise regression analysis. Nine CpGs in MIR29B2CHG, FHL2, TRIM59, ELOVL2, KLF14, and ASPA were selected for regression model construction. A leave-one-out cross-validation analysis revealed the high performance of the age prediction model, with a mean absolute error (MAE) and root mean square error of 4.97 and 6.43 years, respectively. Additionally, our model showed good performance with a MAE of 6.06 years in the analysis of data of 181 costal cartilage samples collected from Europeans. Our model effectively estimates the age of deceased individuals using costal cartilage samples; therefore, it can be a valuable forensic tool for disaster victim and missing person investigation.

Identification success rates in the post-Spanish Civil War mass graves located in the cemetery of Paterna, Spain: Meta-research on 15 mass graves with 933 subjects

Spain suffered a Civil War between 1936 and 1939 that ended with the victory of the National Forces led by General Franco. Once the Spanish Civil War ended, 2238 subjects were executed and buried in several mass graves in the Cemetery of Paterna, one of Spain's largest mass grave sites. Efforts to locate and identify all the victims of the mass graves of the Paterna cemetery are ongoing, but the actual data of the percentage of DNA identifications remains uncertain. Following this, we conducted a meta-research study including 15 mass graves and 933 subjects to determine the DNA identification rates in the mass graves of the Paterna cemetery. We found that the total proportion of identified subjects in the mass graves was 15.9 % (95 % CI: 10.0-22.9). Moreover, we found that the model between the identification success rate (ISR) and the number of relatives that donated DNA (NRTDD) in the mass graves of the cemetery of Paterna was ISR = NRTDD-0.424. Results obtained about the proportion of identified subjects and the model between the ISR and the NRTDD imply the need for a scientific reflection between all the research groups involved in the identification tasks to modify deficiencies and update identification protocols to obtain better future results.

Validation process of automatic DNA extraction from bone material using a new advanced protocol for the EZ2 Connect instrument

Identification of human remains using genetic methods is an important task of forensic science. DNA markers are proving essential in the identification of unknown human remains. However, environmental factors can lead to poor preservation of DNA, including in bone material. The aim of this study was therefore to compare two methods of DNA isolation from bone material: the traditional organic method and the new protocol using the EZ2 Connect instrument. The study involved three types of bone material, namely molars/premolars, petrous parts of the temporal bone and femurs, all with an estimated PMI of 70-80 years. Importantly, the biological material was obtained from three different environments, categorized as preserving, neutral and degrading, based on basic physico-chemical tests and the potential impact on the bone. The results obtained show that the DNA was best preserved in the petrous bone, followed by the teeth, and the femur. DNA extraction using the EZ2 Connect instrument with a new protocol gave slightly better results for the petrous bone, comparable results for the teeth and worse results for the femur compared to the organic method. Several protocol modifications were tested and optimal conditions for DNA isolation were proposed for the EZ2 protocol. Furthermore, the use of an automated method facilitated the effective accumulation of isolates and increased the chances of successful identification of unknown human remains.

Sex estimation research trends in forensic anthropology between 2000 and 2022 in five prominent journals

In forensic anthropology, osteological sex estimation methods are continuously reevaluated and updated to improve classification accuracies. Therefore, to gain a comprehensive understanding of recent trends in sex estimation research in forensic anthropology, a content analysis of articles published between 2000 and 2022 in Forensic Science International, the Journal of Forensic Sciences, the International Journal of Legal Medicine, the American Journal of Biological Anthropology, and Forensic Anthropology, was performed. The main goals of this content analysis were to (1) examine trends in metric versus morphological research, (2) examine which areas of the skeleton have been explored, (3) examine which skeletal collections and population affinities have been most frequently utilized, and (4) determine which statistical methods were commonly implemented. A total of 440 articles were coded utilizing MAXQDA and the resulting codes were exported for analysis. Statistical analyses were conducted utilizing the Cochran-Armitage and Jonckheere-Terpstra tests for trends, as well as Fisher-Freeman-Halton tests. The results demonstrate that sex estimation research published in these journals has prioritized metric over morphological methods. Further, the most utilized skeletal regions continue to be the skull and pelvis, while the most popular classification statistics continue to be discriminant function analysis and logistic regression. This study also demonstrates that a substantial portion of research has been conducted utilizing U.S. and Europe-based collections and limited populations. Based on these results, future sex estimation research must continue exploring the use of long bones and other postcranial elements, testing newer methods of analysis, as well as developing population-inclusive methods.

Reassociation of Skeletal Remains Using Laser-Induced Breakdown Spectroscopy

A major challenge in forensic anthropology and bioarcheology is the development of fast and effective methods for sorting commingled remains. This study assesses how portable laser-induced breakdown spectroscopy (LIBS) can be used to group skeletal remains based on their elemental profiles. LIBS spectra were acquired from the remains of 45 modern skeletons, with a total data set of 8388 profiles from 1284 bones. Spectral feature selection was conducted to reduce the spectral profiles to the peaks exhibiting the highest variation among individuals. Emission lines corresponding to 9 elements (Ca, P, C, K, Mg, Na, Al, Ba, and Sr) were found important for classification. Linear discriminant analysis (LDA) was concurrently used to classify each spectral profile. From the 45 individuals, each LIBS spectrum was successfully sorted to its corresponding skeleton with an average accuracy of 87%. These findings indicate that variation exists among the LIBS profiles of individuals' skeletal remains, highlighting the potential for portable LIBS technology to aid in the sorting of commingled remains.

Quantitative color analysis of burned bone to predict DNA quantity, quality, and genotyping success

Badly burned skeletal remains are commonly submitted to forensic laboratories for victim identification via DNA analysis methods. Burned skeletal remains present many challenges for DNA analysis as they can contain low amounts of DNA which can also be damaged and degraded, resulting in partial or no STR profiles. Therefore, a simple, but effective screening method that identifies which samples may provide the most successful STR or mtDNA typing results for identification would enable forensic laboratories to save time, money, and resources. One metric that can be used and a screening method is the color of burned bone, as bone color changes with exposure to fire as temperature and length of exposure increase. This research developed a quantitative screening method based on the surface color of burned bone. The different visual bone colors (light brown, dark brown, black, gray, and white) were quantified using the Commission on Illumination L*a*b color space. These values were then compared to DNA yield, STR, and mtDNA profile completeness to identify whether the L*a*b values can predict genotyping success. A Bayesian network was constructed to determine the probability of STR typing success, given a set of L*a*b values. Results demonstrated that samples with an a* value greater than or equal to one and b* value greater than eight (light brown and dark brown burned samples) were the most predictive of STR typing success and mtDNA typing success. A decision tree for processing burned bones was constructed based on the color value thresholds.

An optimal skeletal element for DNA testing: Evaluation of DNA quantity and quality from various bone types in routine forensic practice

For human identification, the quality and quantity of DNA must be sufficient for amplification and analysis. When DNA extraction from bone tissues and teeth is required, the optimal skeletal elements should be selected as samples for DNA extraction because DNA yield differs among elements. Recently, some studies have reported that a high quantity of high-quality DNA can be extracted from the small cancellous bones of the hands and feet. In this study, we evaluated the effectiveness of small cancellous bones in the human identification of skeletal remains in routine forensic genetic casework. Cancellous bones [phalanges, (meta)carpal bones, and (meta)tarsal bones)] and the cortical bones (femur and petrous bones) and teeth, which have generally been recommended as samples, were collected from the same individuals that needed identifying using DNA analysis in our laboratory. The quantity of DNA from small cancellous bones tended to be higher than that from cortical bones, and the quality from the former was as high as that from the latter. This study showed that in routine forensic casework, the small cancellous bones of the hands and feet should be actively selected as samples for DNA testing.

Indirect DNA Transfer and Forensic Implications: A Literature Review

Progress in DNA profiling techniques has made it possible to detect even the minimum amount of DNA at a crime scene (i.e., a complete DNA profile can be produced using as little as 100 pg of DNA, equivalent to only 15-20 human cells), leading to new defense strategies. While the evidence of a DNA trace is seldom challenged in court by a defendant's legal team, concerns are often raised about how the DNA was transferred to the location of the crime. This review aims to provide an up-to-date overview of the experimental work carried out focusing on indirect DNA transfer, analyzing each selected paper, the experimental method, the sampling technique, the extraction protocol, and the main results. Scopus and Web of Science databases were used as the search engines, including 49 papers. Based on the results of this review, one of the factors that influence secondary transfer is the amount of DNA shed by different individuals. Another factor is the type and duration of contact between individuals or objects (generally, more intimate or prolonged contact results in more DNA transfer). A third factor is the nature and quality of the DNA source. However, there are exceptions and variations depending on individual characteristics and environmental conditions. Considering that secondary transfer depends on multiple factors that interact with each other in unpredictable ways, it should be considered a complex and dynamic phenomenon that can affect forensic investigation in various ways, for example, placing a subject at a crime scene who has never been there. Correct methods and protocols are required to detect and prevent secondary transfer from compromising forensic evidence, as well as the correct interpretation through Bayesian networks. In this context, the definition of well-designed experimental studies combined with the use of new forensic techniques could improve our knowledge in this challenging field, reinforcing the value of DNA evidence in criminal trials.

A comparison between petrous bone and tooth, femur and tibia DNA analysis from degraded skeletal remains

Skeletal remains are the only biological material that remains after long periods; however, environmental conditions such as temperature, humidity, and pH affect DNA preservation, turning skeletal remains into a challenging sample for DNA laboratories. Sample selection is a key factor, and femur and tooth have been traditionally recommended as the best substrate of genetic material. Recently, petrous bone (cochlear area) has been suggested as a better option due to its DNA yield. This research aims to evaluate the efficiency of petrous bone compared to other cranium samples (tooth) and postcranial long bones (femur and tibia). A total amount of 88 samples were selected from 38 different individuals. The samples were extracted by using an organic extraction protocol, DNA quantification by Quantifiler Trio kit and amplified with GlobalFiler kit. Results show that petrous bone outperforms other bone remains in quantification data, yielding 15-30 times more DNA than the others. DNA profile data presented likeness between petrous bone and tooth regarding detected alleles; however, the amount of DNA extracted in petrous bones allowed us to obtain more informative DNA profiles with superior quality. In conclusion, petrous bone or teeth sampling is recommended if DNA typing is going to be performed with environmentally degraded skeletal remains.

Comparison of DNA preservation and ATR-FTIR spectroscopy indices of cortical and trabecular bone of metacarpals and metatarsals

Shape, size, composition, and function of the bones in the human body vary on the macro, micro and nanoscale. This can influence changes caused by taphonomy and post-mortem preservation, including DNA. Highly mineralised compact bone is less susceptible to taphonomic factors than porous trabecular bone. Some studies imply that DNA can be better preserved in trabecular bone, due to remnants of the soft tissue or bacteria better digesting organic matter while not digesting DNA. The aim of this study was to understand the differences between compact (diaphyses) and trabecular (epiphyses) bone on a molecular level and thus the reasons for the better preservation of the DNA in the trabecular bone. The powder obtained from epiphyses and diaphyses of metacarpals and metatarsals was analysed using ATR-FTIR spectroscopy and compared. Samples with poorest DNA preservation originated from diaphyses, predominantly of metatarsals. They were characterised by higher concentrations of phosphates and crystallinity, while lower collagen quality in comparison to samples with the best DNA preservation. Epiphyses presented higher concentrations of better-preserved collagen while diaphyses had higher concentrations of carbonates and phosphates and higher crystallinity. Due to better-preserved collagen in the epiphyses, the soft tissue remnants hypothesis seems more likely than the bacteria hypothesis.

Diagnostic models to predict nuclear DNA and mitochondrial DNA recovery from incinerated teeth

Teeth are frequently used for human identification from burnt remains, as the structure of a tooth is resilient against heat exposure. The intricate composition of hydroxyapatite (HA) mineral and collagen in teeth favours DNA preservation compared to soft tissues. Regardless of the durability, the integrity of the DNA structure in teeth can still be disrupted when exposed to heat. Poor DNA quality can negatively affect the success of DNA analysis towards human identification. The process of isolating DNA from biological samples is arduous and costly. Thus, an informative pre-screening method that could aid in selecting samples that can potentially yield amplifiable DNA would be of excellent value. A multiple linear regression model to predict the DNA content in incinerated pig teeth was developed based on the colourimetry, HA crystallite size and quantified nuclear and mitochondrial DNA. The chromaticity a* was found to be a significant predictor of the regression model. This study outlines a method to predict the viability of extracting nuclear and mitochondrial DNA from pig teeth that were exposed to a wide range of temperatures (27 to 1000 °C) with high accuracy (99.5-99.7%).

Molecular Taphonomy of Heme: Chemical Degradation of Hemin under Presumed Fossilization Conditions

The metalloporphyrin heme acts as the oxygen-complexing prosthetic group of hemoglobin in blood. Heme has been noted to survive for many millions of years in fossils. Here, we investigate its stability and degradation under various conditions expected to occur during fossilization. Oxidative, reductive, aerobic, and anaerobic conditions were studied at neutral and alkaline pH values. Elevated temperatures were applied to accelerate degradation. High-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) identified four main degradation products. The vinyl residues are oxidized to formyl and further to carboxylate groups. In the presence of air or H₂O₂, cleavage of the tetrapyrrole ring occurs, and hematinic acid is formed. The highest stability of heme was observed under anaerobic reductive conditions (half-life 9.5 days), while the lowest stability was found in the presence of H₂O₂ (half-life 1 min). We confirmed that the iron cation plays a crucial role in degradation, since protoporphyrin IX, lacking iron, remained significantly more stable. Under anaerobic, reductive conditions, the above-mentioned degradation products were not observed, suggesting a different degradation pathway. To our knowledge, this is the first molecular taphonomy study on heme, which will be useful for understanding its fate during fossilization.

Anatomists' uses of human skeletons: Ethical issues associated with the India bone trade and anonymized archival collections

Concerns have recently been expressed about the continuing availability of human bones from India, obtained originally for educational purposes but lacking the requisite informed consent that would be expected today. More generally, a broader claim is being made, namely, that the practice of using any unconsented bones in educational settings is unethical and should cease. These calls, in turn, raise broader issues regarding the availability of anonymous archival collections in anatomy museums. Although this debate centers on undergraduate anatomy teaching, much anthropological research utilizes human remains of past populations for which there can have been no consent. A suggested alternative for undergraduate teaching is the use of 3D images of human bones, rather than the bones themselves. In addressing these issues, the background to the India bone trade is assessed, and the year 1985 is pinpointed as having significant ethical weight. The cultural and ethical interests inherent in studying archival anonymous skeletal material are weighed against indiscriminate reburial. Although any use of unconsented material represents ethical compromise, account should be taken of changing ethical expectations with time. It is concluded that: there is no justification for repatriation or disposal of all bones for which specific informed consent has not been obtained; continued use of anonymous archival human bones in a professional setting is acceptable, even in the absence of informed consent, with the proviso that there are no culturally relevant groups seeking repatriation; the continued existence of bones in long-standing private collections cannot be justified since it amounts to long-term storage with no identified goals; the notion that 3D images are an ethically superior alternative to actual human bones is unsustainable, since there is an intimate connection between the bones and the 3D images.

Rickettsia felis DNA recovered from a child who lived in southern Africa 2000 years ago

The Stone Age record of South Africa provides some of the earliest evidence for the biological and cultural origins of Homo sapiens. While there is extensive genomic evidence for the selection of polymorphisms in response to pathogen-pressure in sub-Saharan Africa, e.g., the sickle cell trait which provides protection against malaria, there is inadequate direct human genomic evidence for ancient human-pathogen infection in the region. Here, we analysed shotgun metagenome libraries derived from the sequencing of a Later Stone Age hunter-gatherer child who lived near Ballito Bay, South Africa, c. 2000 years ago. This resulted in the identification of ancient DNA sequence reads homologous to Rickettsia felis, the causative agent of typhus-like flea-borne rickettsioses, and the reconstruction of an ancient R. felis genome.

Forensic DNA extraction methods for human hard tissue: A systematic literature review and meta-analysis of technologies and sample type

DNA identification of human remains has a valuable role in the field of forensic science and wider. Although DNA is vital in identification of unknown human remains, post-mortem environmental factors can lead to poor molecular preservation. In this respect, focus has been placed on DNA extraction methodologies for hard tissue samples, as these are the longest surviving. Despite decades of research being conducted on DNA extraction methods for bone and teeth, little consensus has been reached as to the best performing. Therefore, the aim of this study was to conduct a thorough systematic literature review to identify potential DNA extraction technique(s) which perform optimally for forensic DNA profiling from hard tissue samples. PRISMA guidelines were used, by which a search strategy was developed. This included identifying databases and discipline specific journals, keywords, and exclusion and inclusion criteria. In total, 175 articles were identified that detailed over 50 different DNA extraction methodologies. Results of the meta-analysis conducted on 41 articles - meeting further inclusion criteria - showed that statistically significant higher DNA profiling success was associated with solid-phase magnetic bead/resin methods. In addition, incorporating a demineralisation pre-step resulted in significantly higher profiling successes. For hard tissue type, bone outperformed teeth, and even though dense cortical femur samples were more frequently used across the studies, profiling success was comparable, and in some cases, higher in cancellous bone samples. Notably, incomplete data sharing resulted in many studies being excluded, thus an emphasis for minimum reporting standards is made. In conclusion, this study identifies strategies that may improve success rates of forensic DNA profiling from hard tissue samples. Finally, continued improvements to current methods can ensure faster times to resolution and restoring the identity of those who died in obscurity.

An analysis of data curated from 5 years of identifying human remains

An archive of 5 years of cases involving the identification of human remains was curated, collecting information on: The sample type submitted, the number of STR loci yielding interpretable results, the kinship challenge posed, and the outcome for the case. A total of 129 cases of remains ID were investigated using manual DNA extraction and recovery methods with amplification of STR markers using the Power Plex 21 multiplex STR kit from Promega Corp. In 52 cases, blood spots collected by the ME were provided as sample and in 100% of those cases, probabilities of relatedness to the reference samples was ≥99%. In 77 cases, tissue other than blood was provided as a source of DNA. These other samples were grouped categorically into long bones (femur and tibia; 40 cases), skull bones/teeth (11 cases), other bones (16 cases), and tissue (normally adherent to bone) (10 cases). Reference samples provided for cases included alleged parents or child(ren) of the victim (86 cases), alleged full siblings of the victim (38 cases), or alleged second-order relatives (five cases). The overall success rate in confirming the identity of the source of the remains in these cases was 89.2%. Our results demonstrate that a laboratory can be often successful identifying human remains using methods easily implemented in any DNA typing laboratory.

Kinship analysis of skeletal remains from the Middle Ages

Medieval cemeteries Klisa-Guca Gora, Alihodze and Glavica-Han Bila located in the Travnik area (Travnik, Bosnia and Herzegovina) were archaeologically examined in the period 2011-2014, revealing human skeletal remains of 11 individuals in total. Archaeological skeletal samples, previously deposited in Travnik Homeland Museum (Travnik, Bosnia and Herzegovina) were subjected to genetic analysis. The aim of this research was to test familiar relationship of 11 individuals excavated from three medieval cemeteries and to predict Y-haplogroup for male individuals. In order to perform molecular-genetic characterisation of collected human skeletal remains, two systems of genetic markers were analysed: autosomal and Y-STR loci. Complete or partial data obtained by autosomal STR typing of 11 individuals were subjected to kinship analysis. Male sex was determined in eight samples out of 11. Direct relatives of the "brother-brother" type were detected in one case with high kinship probability (KP) value of 99.99996 %. Complete or nearly complete and usable Y-STR profiles were obtained for six out of eight male individuals. The presence of identical haplotypes at Y-STR loci and results of Y-haplogroup prediction suggest that all male individuals share the same paternal lineage and belong to J2a haplogroup. Overall, this study emphasises the usefulness, efficiency and sensitivity of STR markers in the molecular-genetic characterisation of old skeletal remains as well as the importance of employing additional markers like Y-STRs in archaeogenetic studies, besides traditionally used autosomal STR markers, in order to get a comprehensive information about close and distant relatives, and ancestry.

Public and family support and concerns for providing DNA to law enforcement in long-term missing person cases

The identification of long-term missing persons and unidentified human remains is a global challenge. Many people stay on missing persons registers, with unidentified human remains stored for extended periods in mortuaries around the world. Research exploring public and/or family support for providing DNA in long-term missing persons cases is scarce. The aims of this study were to examine whether trust in police predicted the level of support for providing DNA and explore public/family support and concerns for providing DNA in such cases. Trust in police was measured through two widely used empirical attitude scales; "The Measures of Police Legitimacy and Procedural Justice". Support and concerns for giving DNA were measured through four hypothetical missing persons case scenarios. The results showed more positive attitudes towards police legitimacy and procedural justice significantly predicted support, with the percentage level of positive support across the four case types as follows: cases involving a long-term missing child (89%), elderly adult with dementia (83%), young adult with a history of runaway (76%), with the lowest level of support for an adult with an estranged family (73%). Participants also reported more concerns about providing DNA when the missing person circumstances involved family estrangement. Understanding levels of public/family support and concerns around providing DNA to police in missing persons cases is vital to ensure that DNA collection practices reflect what the public/family support and, wherever possible, alleviate public concerns.

Methodological Changes in the Field of Paleogenetics

Paleogenetics has significantly changed since its inception almost forty years ago. Initially, molecular techniques available to the researchers offered minimal possibilities for ancient DNA analysis. The subsequent expansion of the scientific tool cabinet allowed for more remarkable achievements, combined has with the newfound popularity of this budding field of science. Finally, a breakthrough was made with the development of next-generation sequencing (NGS) technologies and the update of DNA isolation protocols, through which even very fragmented aDNA samples could be used to sequence whole genomes. In this paper, we review the achievements made thus far and compare the methodologies utilized in this field of science, discussing their benefits and challenges.

Dead migrants in the Mediterranean: genetic analysis of bone samples exposed to seawater

In April 2015, a fishing boat that departed from Libya with about 1,000 migrants on board sank in the Mediterranean Sea. Most of the migrants were packed in the hull of the boat and drowned in the shipwreck. After fifteen months, the ship was recovered from the seabed and brought to a Sicilian naval area for forensic investigations. Skeletal remains belonging to more than 700 people were retrieved. A selected sample composed of 80 victims was considered in order to evaluate the possibility of achieving genetic profiles useful for a positive identification from these challenging specimens. The molecular features of the DNA recovered from a significant number of real casework samples exposed to seawater for long periods of time were described for the first time. Three different DNA extraction protocols and three different commercial kits were employed in order to generate genetic profiles based on the characterization of 21 autosomal STR loci. The combination of multiple DNA extractions and the cross-checking of multiple PCR amplifications with different kits allowed to obtain reliable genetic profiles characterized by at least 16 STR markers in more than 70% of the samples. The factors that could have affected the different quality of the genetic profiles were investigated and the bone preservation was examined through microscopic and macroscopic analyses. The approach presented in this study could be useful in the management of the genetic analysis of bone samples collected in other similar DVI scenarios. The genetic profiles recovered from the bone samples will be compared in kinship analysis to putative relatives of the victims collected in Africa in order to obtain positive identifications.

Comparison of DNA preservation between ribs and vertebrae

The choice of skeletal element types and their intra-bone parts is important because of differences in DNA preservation, and this must be considered when sampling bones for DNA testing. When incomplete skeletons are found, ribs and vertebrae have been shown to be the most suitable for genetic identification of bones from the torso. This study compares the preservation of DNA between 12th thoracic vertebrae and first ribs to determine which bone type is more suitable for genetic typing. The study analyzed 35 12th thoracic vertebrae and 29 first ribs from one mass grave from the Second World War with commingled skeletal remains excavated. Bone DNA preservation was estimated by measuring nuclear DNA concentration and its degradation and through short tandem repeat (STR) typing success. Previous studies performed on aged skeletal remains have shown that the DNA content of the first ribs and 12th thoracic vertebrae has high intra-bone variability, and this was considered when sampling the bones. After full demineralization extraction, the PowerQuant System (Promega) was used to measure the quantity and quality of DNA, and the GlobalFiler kit (Applied Biosystems) was used for STR typing. The results showed that DNA yield and degradation and STR typing success exhibited no statistically significant difference between first ribs and 12th thoracic vertebrae, and there was no intra-individual difference when comparing only paired bones from the same individuals. Consequently, with intra-bone DNA variability considered, the first ribs or the 12th thoracic vertebrae can be selected when sampling to genetically identify the skeletal remains of highly degraded torsos. HIGHLIGHTS: The first ribs and thoracic vertebrae are the most suitable bones for sampling from the torso. The proximal part of first rib and posterior vertebral column of the 12th thoracic vertebrae yielded the most DNA. The first ribs were compared with the 12th thoracic vertebrae, and the sampling process considered intra-bone DNA variability. The quality and quantity of nuclear DNA and success of STR typing were measured. The first ribs yielded the same DNA yields as well as STR typing success as the 12th thoracic vertebrae. When only the torso is present, it is not of high importance whether the first ribs or the 12th thoracic vertebrae are collected.

Quantifying the potential of morphological parameters for human dental identification: part 3-selecting the strongest skeletal identifiers in the mandible

The current study aimed to select the best mandibular morphological identifiers. One-hundred eighty-five panoramic radiographs were retrospectively collected, in which four landmarks were located on the mandible: the most superior point of the condyle right/left (CONR/L), of the coronoid right/left (CORR/L), of the mandibular lingula right/left (LINR/L), and the most mesial point of the mental foramen right/left (MMFR/L). Five linear measurements, 6 angles, and 10 ratios were measured bilaterally. Three groups of statistics were considered: (1) mean potential set; (2) inter-observer agreement quantified by intra-class correlation (ICC) and within-subject coefficient of variation (WSCV); and (3) Spearman correlation. Parameters were selected for a step-by-step cascade. In a univariate approach, the following parameters proved to have the best identifying capacity: ratio 3 right (between lines CONR - CORR and LINR - MMFR) with mean potential set 13%, ICC 0.90, and WSCV 4.8%; ratio 4 (between lines CONR/L - CORR/L and MMFR - MMFL) with mean potential set 13%, ICC 0.92, and WSCV 8.9%; and angle 4 left (between landmarks LINL, MMFL, and MMFR) with mean potential set of 18%, ICC 0.91, and WSCV 1.2%. The correlation coefficients ranged from 0.01 to 0.33. In a multivariate approach, the identifying capacity improved drastically, with all ratios combined as the strongest identifier (mean potential set 1.29%). In conclusion, a single ratio or a single angle already narrows down the set of potential matches, but the mean potential set remains relatively large. Combining all ratios drastically increases the certainty of the match.

Genomics of Ancient Pathogens: First Advances and Prospects

Paleogenomics is one of the urgent and promising areas of interdisciplinary research in the today's world science. New genomic methods of ancient DNA (aDNA) analysis, such as next generation sequencing (NGS) technologies, make it possible not only to obtain detailed genetic information about historical and prehistoric human populations, but also to study individual microbial and viral pathogens and microbiomes from different ancient and historical objects. Studies of aDNA of pathogens by reconstructing their genomes have so far yielded complete sequences of the ancient pathogens that played significant role in the history of the world: Yersinia pestis (plague), Variola virus (smallpox), Vibrio cholerae (cholera), HBV (hepatitis B virus), as well as the equally important endemic human infectious agents: Mycobacterium tuberculosis (tuberculosis), Mycobacterium leprae (leprosy), and Treponema pallidum (syphilis). Genomic data from these pathogens complemented the information previously obtained by paleopathologists and allowed not only to identify pathogens from the past pandemics, but also to recognize the pathogen lineages that are now extinct, to refine chronology of the pathogen appearance in human populations, and to reconstruct evolutionary history of the pathogens that are still relevant to public health today. In this review, we describe state-of-the-art genomic research of the origins and evolution of many ancient pathogens and viruses and examine mechanisms of the emergence and spread of the ancient infections in the mankind history.

Not so simple: Understanding the complexities of establishing identity for cases of unidentified human remains in an Australian medico-legal system

Discussions regarding the importance and complexities associated with the identification of deceased persons have typically focused on disaster or humanitarian contexts where there has been large scale loss of life. In contrast, identification efforts for unidentified human remains (UHR) cases in routine domestic casework contexts have received relatively little attention. The aim of this paper was to present the situation regarding the count of UHR cases in the state of Victoria, Australia, dating between 1960 and 2020, and to provide a constructively critical appraisal of the factors that have, and continue to, hinder their identification. Over the six decades a total of 132 coronial cases remained unidentified; an average of 2-3 cases per annum. For each case, the preservation of the remains, geographical location of where they were recovered from, primary (fingerprints, dental, DNA) and secondary identification methods that had been employed, potential for additional identification testing and current curation of the remains, were recorded. The difficulty with providing a "total count" of UHR cases is discussed, as well as the ways in which preservation, availability of identification methods, changes in policies and procedures, record management, changes in practice and advancements in technology, have impacted the identification process. This paper demonstrates the complexity of the investigation of UHR cases, and why individuals continue to remain unidentified in 2021.

Streamlining the decision-making process for international DNA kinship matching using Worldwide allele frequencies and tailored cutoff log10LR thresholds

The identification of human remains belonging to missing persons is one of the main challenges for forensic genetics. Although other means of identification can be applied to missing person investigations, DNA is often extremely valuable to further support or refute potential associations. When reference DNA samples cannot be collected from personal items belonging to a missing person, a direct DNA identification cannot be carried out. However, identifications can be made indirectly using DNA from the missing person's relatives. The ranking of likelihood ratio (LR) values, which measure the fit of a missing person for any given pedigree, is often the first step in selecting candidates in a DNA database. Although implementing DNA kinship matching in a national environment is feasible, many challenges need to be resolved before applying this method to an international configuration. In this study, we present an innovative and intuitive method to perform international DNA kinship matching and facilitate the comparison of DNA profiles when the ancestry is unknown or unsure and/or when different marker sets are used. This straightforward method, which is based on calculations performed with the DNA matching software BONAPARTE, Worldwide allele frequencies and tailored cutoff log₁₀LR thresholds, allows for the classification of potential candidates according to the strength of the DNA evidence and the predicted proportion of adventitious matches. This is a powerful method for streamlining the decision-making process in missing person investigations and DVI processes, especially when there are low numbers of overlapping typed STRs. Intuitive interpretation tables and a decision tree will help strengthen international data comparison for the identification of reported missing individuals discovered outside their national borders.

Taphonomic study on drowned victims in a non-sequestered aquatic environment in the Mediterranean Sea

Human decomposition in sea water poses several challenges to forensic practitioners tasked with the analysis of drowned bodies. Postmortem changes in the marine environment have not been extensively investigated and the current literature is mainly based on bodies retrieved from shallow waters or on limited samples. On 18 April 2015, a fishing boat carrying allegedly 1,000 migrants sank in the Mediterranean Sea. In a fifteen-month time span, humanitarian missions were carried out to recover the bodies from the sea. The present study investigates postmortem changes on the drowned victims in a non-sequestered environment in the Mediterranean Sea. A retrospective study was performed by two observers on the autopsy photographic records in the series of bodies recovered from the open sea. For 184 bodies, the postmortem changes were evaluated according to facial, body, limb, and total aquatic decomposition score (FADS, BADS, LADS, TADS, respectively). Furthermore, a modification to the current scoring system that divides upper and lower limbs was suggested. The interobserver agreement was assessed using Krippendorff's alpha coefficient. Possible relations between the decomposition scores and PMSI were investigated with Pearson correlation analysis. According to the sequence of the recovery missions, increasing FADS, BADS, LADS, and TADS were observed. The modified scoring system showed a strong agreement between observers, allowing a more accurate description of the actual extent of decomposition. The scores showed a significant relation with the PMSI (p < 0.01). Prolonged submersion in the open marine environment was confirmed to show increasing decomposition rates, from moderate decay to full disarticulation. This study provides a descriptive unicum of the postmortem changes in the open sea, which may contribute to strengthen the discipline and aid description of bodies recovered in similar circumstances, especially if a body needs to be associated to a disaster or period with respect to another, thus facilitating families or authorities in the search for specific victims.

Direct STR typing from human bones

Identification by STR analysis of bones is time-consuming, mainly due to the lengthy decalcification required and complex DNA extraction process. To streamline this process, we developed a direct STR typing protocol from bone samples. We optimized bone sample amounts using femur and tibia and two commercial PCR kits (Identifiler™ Plus and IDplex Plus kits). Optimally, 100 mg of bone powder in 300 µL PBS buffer was heated at 98 °C for three minutes to produce a supernatant for DNA amplification. IDplex Plus performed better than Identifiler™ Plus in terms of allele recovery and peak height. Fifteen samples of each of seven bone elements (1st distal phalange of hand, capitate, femur, metacarpal 4, patella, talus, and tibia; N = 105) were then subjected to direct STR typing with the optimized protocol, and 94.3% were high partial to full profiles. The performance of the developed protocol was similar for all bone elements. Median peak heights were significantly better in profiles of cancellous bone than compact bone (p = 0.033) and significantly different across the bone elements (p < 0.001). Ten casework samples from various conditions and up to 7-year-PMI were subjected to both direct STR and conventional STR typing. No significant difference in the number of alleles was seen (95% HDI of -13.5 to 5.15). As well as being rapid, convenient, and safe, the protocol could help improve STR typing from bones.

Study of Sexual Dimorphism in Metatarsal Bones: Geometric and Inertial Analysis of the Three-Dimensional Reconstructed Models

The aim of the present paper is to determine the sex of the individual using three-dimensional geometric and inertial analyses of metatarsal bones. Metatarsals of 60 adult Chinese subjects of both sexes were scanned using Aquilion One 320 Slice CT Scanner. The three-dimensional models of the metatarsals were reconstructed, and thereafter, a novel software using the center of mass set as the origin and the three principal axes of inertia was employed for model alignment. Eight geometric and inertial variables were assessed: the bone length, bone width, bone height, surface-area-to-volume ratio, bone density, and principal moments of inertia around the x, y, and z axes. Furthermore, the discriminant functions were established using stepwise discriminant function analysis. A cross-validation procedure was performed to evaluate the discriminant accuracy of functions. The results indicated that inertial variables exhibit significant sexual dimorphism, especially principal moments of inertia around the z axis. The highest dimorphic values were found in the surface-area-to-volume ratio, principal moments of inertia around the z axis, and bone height. The accuracy rate of the discriminant functions for sex determination ranged from 88.3% to 98.3% (88.3%-98.3% cross-validated). The highest accuracy of function was established based on the third metatarsal bone. This study showed for the first time that the principal moment of inertia of the human bone may be successfully implemented for sex estimation. In conclusion, the sex of the individual can be accurately estimated using a combination of geometric and inertial variables of the metatarsal bones. The accuracy should be further confirmed in a larger sample size and be tested or independently developed for distinct population/age groups before the functions are widely applied in unidentified skeletons in forensic and bioarcheological contexts.

A novel approach for rapid cell assessment to estimate DNA recovery from human bone tissue

We report on the use of a DNA staining dye to locate and record nucleated osteocytes and other bone-related cells within sections of archived formalin-fixed and paraffin-embedded human tibia from which informative DNA profiles were obtained. Eleven of these archived tibia samples were sectioned at a thickness of 5 µm. Diamond™ Nucleic Acid Dye was applied to the sections and cells within the matrix of the bone fluoresced so that their location and number of cells could be photographed. DNA was isolated from these 11 samples using a standard extraction process and the yields were quantified by real-time PCR. Complete STR profiles were generated from ten bone extracts where low-level inhibition was recorded with an incomplete STR profile obtained from one sample with higher inhibition. The stained image of this sample showed that few cells were present. There was a significant relationship between the number of DD-stained cells and the number of alleles obtained (p < 0.05). Staining cells to determine the prevalence of bone cell nuclei allows a triage of samples prior to any subsequent DNA profiling.

Intra-bone nuclear DNA variability and STR typing success in Second World War 12th thoracic vertebrae

Bones are an important source of DNA for identification in forensic medicine, especially when the remains are skeletonized, which is the case when dealing with victims of the Second World War. Often the amount of bone available for sampling is limited, and therefore it is crucial to sample the bone segment with the highest adequate DNA quantity for identification. Studies performed on all representative skeletal element types of the human body showed that the amount of DNA obtained from different skeletal elements of different body regions varies greatly. When bones from torso were analyzed, thoracic vertebrae outperformed other vertebrae (cervical and lumbar) and, alongside the first ribs, were among the most appropriate bone elements for identification purposes. It was also shown that the quantity of DNA varies significantly within a single bone type. This study focused on exploring intra-bone DNA variability between five parts of 12th thoracic vertebrae (laminae + spinous process, pedicles + transverse processes, and corpus right, left, and middle). The research was based on the theory that the distribution of body weight and consequently bone remodeling, as well as the ratio between cancellous and cortical bone, contribute to different quantities of DNA in different parts of vertebra sampled. The vertebrae were cleaned and cut into five parts, and each part was completely ground to obtain homogenous bone powder. Half a gram of powder from each part was decalcified using a full demineralization extraction method. The DNA was purified in a Biorobot EZ1 machine (Qiagen). DNA quantity and quality were determined using the PowerQuant System (Promega) and autosomal STR typing success using the GlobalFiler Amplification Kit (Applied Biosystems). Thirty-five 12th thoracic vertebrae were sampled from a single Second World War mass grave. The best results with the highest DNA quantity were found in laminae and the spinous process, and among them all vertebrae analyzed yielded full STR profiles except three, where only a few dropouts occurred. The second-ranked bone part was the pedicles and transverse processes. The comparison of DNA degradation in the vertebral segments analyzed does not show statistically significant differences. Considering our research, when only the torso is available for identification, the 12th thoracic vertebra should be collected and the vertebral arch should be sampled for genetic analyses.

Comparison of nuclear DNA yield and STR typing success in Second World War petrous bones and metacarpals III

DNA yield and STR typing success differ among skeletal element types and within individual bones. Consequently, it is necessary to identify the skeletal elements and their intra-skeletal parts that will most likely yield utilizable and informative endogenous DNA for human identification of skeletal remains. The petrous portion of the temporal bone has been shown to be the most suitable skeletal part for sampling archaeological skeletons, and it has also been used successfully in some forensic cases. When all representative bone types were analyzed for three complete Second World War skeletons, metatarsals and metacarpals yielded more DNA than petrous bones (which generated full profiles even if the DNA yield was lower) and, among almost 200 Second World War metatarsals and metacarpals analyzed, metacarpals III were found to be the highest-yielding bones. To further improve the sampling strategy in DNA analysis of aged skeletal remains, a comparison between 26 petrous bones and 30 metacarpals III from Second World War skeletons was made considering intra-bone DNA yield variability. In metacarpals III only epiphyses were sampled, and in petrous bones only the dense part within the otic capsule was used. To exclude the influence of taphonomic issues as much as possible, petrous bones and metacarpals III from a single Second World War mass grave were examined. The difference between petrous bones and metacarpals III was explored by measuring nuclear DNA yield and success of STR typing. After cleaning the samples, full demineralization extraction was used to decalcify 0.5 g of powdered bone. PowerQuant (Promega) was used to determine DNA content and DNA degradation rates, and STR typing was performed using the PowerPlex ESI 17 Fast System (Promega). Metacarpals III produced the same DNA yields and STR typing success as petrous bones with no intra-individual difference observed in concentration of DNA, degradation rate, percentage of successfully amplified alleles, and intensity of electrophoretic signals. Sampling and processing of metacarpal III epiphyses is consequently recommended for genetic identification of highly degraded skeletal remains in routine forensic casework and in buried non-commingled aged skeletal remains whenever metacarpals III are preserved. Metacarpals III are easy to sample and less prone to contamination with modern DNA because no saw is needed for sampling in comparison to the petrous portion of the temporal bone. The data obtained in this study further improve the sampling strategy for genetic identification of Second World War skeletal remains in Slovenia.

Intra-bone nuclear DNA variability and STR typing success in Second World War first ribs

DNA sampling and typing are used for identifying missing persons or war victims. In recent forensic studies, little focus has been placed on determining intra-bone variability within a single skeletal element. When dealing with aged human bones, complete skeletal remains are rarely present. In cases in which only the torso is available, studies have shown that ribs are one of the most appropriate samples, but intra-bone variability has not yet been studied. A higher degree of remodeling was found to contribute to higher DNA yield in the parts of the skeletal element where the most strain is concentrated. This study explores intra-bone variability in proximal, middle, and distal parts of the first human rib by determining the quantity and quality of DNA using the PowerQuant System (Promega) and autosomal STR typing success using the PowerPlex ESI 17 Fast System (Promega). Thirty first ribs from a single Second World War mass grave were sampled. No variation in DNA degradation was observed across the individual rib. The highest quantity of DNA was measured in the proximal part of the first rib, and in all ribs except three, full or almost full genetic profiles were obtained. Thus, when only the torso is present in archaeological or medico-legal cases, first ribs are recommended to be collected if possible, and the proximal or vertebral ends should be sampled for genetic analysis.

The human intervertebral disc as a source of DNA for molecular identification

Genetic analyses such as STR-typing are routinely used for identification purposes in forensic casework. Although genotyping techniques only require a minimum amount of DNA to provide a genetic profile, DNA quality differs not only between but also within tissues during ongoing decomposition. Initiated by a recent case where, due to the constitution of the body, preferred tissue was not available or only resulted in a partial and not usable DNA profile, the analysis of intervertebral discs as a source of DNA was considered. As the analysis of this tissue resulted in a high quality DNA profile a further study was performed in which thirty intervertebral discs dissected from bodies in different stages of decay were analyzed. All samples yielded good quality DNA in quantities suitable for STR-based amplification with no or only low degradation indices, resulting in complete genetic profiles. These results demonstrate the robustness of human intervertebral disc tissue as a source of DNA for molecular identification purposes.

Postmortem interval assessment by MALDI-TOF mass spectrometry analysis in murine cadavers

Aims

This study assessed the use of matrix‐assisted laser desorption/ionization time of flight (MALDI‐TOF) mass spectrometry as an alternative method to identify species associated with the thanatomicrobiota and epinecrotic communities.

Methods and Results

The study was conducted on 10 murine cadavers, and microbiological swabs were collected from five external anatomical sites (eyes, ears, nose, mouth and rectum) and four internal organs (brain, spleen, liver, heart), during 16 and 30 days, for the thanatomicrobiota and epinecrotic communities, respectively. Our results revealed that the postmortem microbiota associated with the external cavities showed changes over time and reduced taxonomic diversity. The internal organs, initially sterile, showed signs of microbial invasion at 3 and 10 days postmortem for the liver‐spleen and heart‐brain, respectively. The postmortem microbiota was mainly dominated by Firmicutes and Proteobacteria.

Conclusions

MALDI‐TOF is a promising method for estimating postmortem interval (PMI), associated with rapid sample handling, good reproducibility and high productivity.

Significance and Impact of the Study

This study investigated microbial changes during the decomposition process and proposed a simple strategy for PMI estimation. Results introducing the application of the MALDI‐TOF method in the field of forensic.

Uniparental genetic markers in Native Americans: A summary of all available data from ancient and contemporary populations

OBJECTIVES

The aim of this study was to create a comprehensive summary of available mtDNA and Y-chromosome data for Native Americans from North, Central, and South America, including both modern and ancient DNA. To illustrate the usefulness of this dataset we present a broad picture of the genetic variation for both markers across the Americas.

METHODS

We searched PubMed, ResearchGate, Google Scholar for studies about mtDNA or Y-chromosome variation in Native American populations, including geographic, linguistic, ecological (ecoregion), archeological and chronological information. We used AMOVA to estimate the genetic structure associated with language and ecoregion grouping and Mantel tests to evaluate the correlation between genetic and geographic distances.

RESULTS

Genetic data were obtained from 321 primary sources, including 22,569 individuals from 298 contemporary populations, and 3628 individuals from 202 archeological populations. MtDNA lineages of probable non-Amerindian origin were rare, in contrast with Y-chromosome lineages. Mantel tests showed a statistically significant correlation for the whole continent considering mtDNA but not the Y-chromosome. Genetic structure between groups was always stronger for mtDNA than for the Y-chromosome.

CONCLUSIONS

This study summarizes decades of research conducted in Native American populations for both mtDNA and the Y-chromosome. Continental or sub-continental patterns of variation reveal that most of the genetic variation occurs within populations rather than among linguistic or ecoregional groups, and that isolation by distance is barely detectable in most population sets. The genetic structure among groups was always larger for mtDNA than for the Y-chromosome, suggesting between-sex differences in gene flow.

Efficacy of a novel bone preprocessing method for better DNA yield

In cases involving identification of missing persons, mass disasters and ancient DNA investigations, bone and teeth samples are often the only, and almost always the best, biological material available for DNA profiling. Standard methods for extraction of DNA from such samples involve grinding of the bone and teeth samples. Here, we present an extremely efficient protocol for recovery of DNA from bone samples by a method of scrapping. The study was carried out on 25 samples and it was found that the quantity of DNA isolated by the scrapping method was up to 1.131 ng/µl with a success rate of 93% as compared to a much lower yield of 0.359 ng/µl DNA isolated with a success rate of 28% through the grinding method. The scrapping method of DNA extraction has been proven to be extremely useful in forensic examination of challenging samples that had multiple failures using the traditional grinding method.

Sweet tooth: DNA profiling of a cranium from an isolated retained root fragment

Sampling of healthy multi‐rooted teeth is recommended for the genetic identification of human skeletal remains. However, this may not always be possible, as in the reported case consisting of an isolated human cranium found in an aggregate crushing and processing plant in Piedmont, Northwest Italy. The cranium displayed significant weathering, suggesting a post‐mortem interval of several years, and was edentulous with the exception of the apical root fragment of the upper left canine, consequence of an antemortem horizontal fracture. Prolonged decalcification of the root fragment followed by powder‐free DNA extraction from ~10 mg of root tip tissue led to the recovery of >10 ng of high molecular weight human DNA, in comparison with ~0.01 ng of DNA per mg of bone powder obtained from the petrous portion of the temporal bone. Quantity and quality of DNA isolated from apical tooth tissue enabled multiple genotyping, including a reportable female STR profile, mitochondrial DNA analysis, and ancestry‐informative insertion/deletion polymorphisms. Although the cranium remained unidentified after DNA comparisons, our findings confirm that apical tooth tissue is a promising source of DNA, easily obtained through a powder‐free extraction protocol. Results also indicate that root tips should not be overlooked in challenging identification cases, even in the presence of compromised tooth specimens.

Intrinsic and extrinsic factors that may influence DNA preservation in skeletal remains: A review

The identification of skeletal human remains, severely compromised by putrefaction, or highly deteriorated, is important for legal and humanitarian reasons. There are different tools that can help in the identification process such as anthropological and genetic studies. The success observed during the last decade in genetic analysis of skeletal remains has been possible especially due to the refinements of DNA extraction and posterior analysis techniques. However, despite these progresses, many challenges keep influencing the results of such analysis, mainly the limited amount and the degradation of the DNA recovered from badly preserved samples. By now, there is still no wide-range knowledge about post-mortem kinetics of DNA degradation. Therefore, taphonomy studies can play a key role in the reconstruction of post-mortem transformations that skeletal remains, and consequently DNA, have undergone. Thus, the goal of the present review focuses on the assessment of the literature regarding the possible effect of intrinsic (characteristics of the bone) and extrinsic (environmental) factors on the state of preservation of skeletal remains recovered in a terrestrial environment and their genetic material. The establishment of useful indicators describing the state of the remains is a key factor in order to determine their suitability for posterior biomolecular analysis.

Assessment of the ANDE 6C Rapid DNA system and investigative biochip for the processing of calcified and muscle tissue

The ANDE 6C Rapid DNA system could offer a potential alternative for the processing of calcified and soft tissue samples, often encountered in mass disaster scenarios. While originally designed for single source buccal swabs, interest in the performance of these instruments when using other types of single source samples continues to grow. To enhance the recovery of otherwise lesser quality samples, the manufacturer developed the investigative biochip, an alternative to the NDIS approved Arrestee biochip for reference sample buccal swabs. This study explores the viability of using the ANDE 6C system and the investigative biochip to process soft and calcified tissue, and uses conventional sample processing to contrast the results. Though the success rate obtained using the instrument's expert system was lower than expected - 0% muscle, 11% ribs, and 50% teeth -, the ANDE 6C offers an advantage over conventional calcified tissue processing in terms of turn-around time and processing complexity. If robust analysis parameters can be established to allow the evaluation of the generated data by a qualified analyst on a third party software platform, the use of the ANDE 6C and investigative biochip could be a suitable alternative for currently employed procedures. However, as is the case with conventional DNA typing, the quantity, age, type of biological material and quality of the exemplars could all play a role in the success of the ANDE 6C typing process. In addition, it appears as if the calcified tissue pre-processing protocol that provides the better opportunity for the ANDE 6C success is not appropriate to be carried out in the field or by non-trained personnel as special equipment as well as a certain level of exe expertise and technique is necessary. Nevertheless, disaster victim and unidentified human remain samples could be processed in a laboratory setting using the Rapid DNA ANDE 6C platform provided sufficient material is available to conduct a second, 'rescue' sample processing if necessary.

Intra-bone nuclear DNA variability in Second World War metatarsal and metacarpal bones

DNA analysis of Second World War skeletal remains is challenging because of the limited yield of DNA that is usually recovered. Recent forensic research has focused on determining which skeletal elements are superior in their preservation of DNA, and little focus has been placed on measuring intra-bone variability. Metatarsals and metacarpals outperformed all the other bones in DNA yield when analyzing all representative skeletal elements of three Second World War victims, and intra-bone variability was not studied. Soft-tissue remnants were found to contribute to higher DNA yield in trabecular bone tissue. Because metatarsals and metacarpals are composed of trabecular epiphyses and a dense diaphysis, the goal of this study was to explore intra-bone variability in DNA content by measuring nuclear DNA quantity and quality using the PowerQuant System (Promega). A total of 193 bones from a single Second World War mass grave were examined. From each bone, DNA was extracted from the compact diaphysis and from both spongy epiphyses combined. This study confirms higher DNA quantity in epiphyses than diaphyses among all the bones analyzed, and more DNA was obtained from metacarpal epiphyses than from metatarsal epiphyses. Therefore, whenever the possibility for sampling both metacarpals and metatarsals from skeletal remains exists, collecting metacarpals is recommended. In cases in which the hands are missing, metatarsals should be sampled. In any case, epiphyses are a richer source of DNA than diaphyses.

Factors influencing DNA extraction from human skeletal remains: bone characteristic and total demineralization process

Background

The extraction of DNA from skeletal remains with good quality and quantity is often challenging for the ability to generate DNA typing. Previous studies demonstrated the DNA extraction with total demineralization from fresh teeth and bones; however, the application in old skeletal remains has been less performed. To obtain good quality and high yield of DNA amount extracted from skeletal remains, the objective of this study was focused on exploring the factors influencing the total demineralization process to obtain developing effective methods.

Results

The concentration of EDTA was found to significantly enhance calcium chelation from the bone while pH of EDTA solution, incubation temperature, incubation time, and volume of EDTA solution were not significant. The optimal condition of total demineralization obtained from Placket-Burmann results represented good-quality DNA and the highest concentration of extracted DNA yield. Subsequently, the STR typing in some bone specimens processed by total demineralization process prior to DNA extraction was improved.

Conclusions

EDTA concentration was a key influencing factor on the total demineralization process to chelate calcium from human skeletal remains. The total demineralization process in old bone specimens probably improved the STR profiles.

Coronal and sagittal suture lengths as novel measurements for sex identification in a sample from the Egyptian population

Sex estimation from isolated or fragmented bones is a cornerstone in medicolegal identification. The current study aimed to estimate sex from the lengths of the coronal and sagittal sutures in a sample of Egyptians. The study was performed on a total of 80 adult cadavers (48 males and 32 females) during a routine autopsy. After exposure of the skull vault, the lengths of the coronal and sagittal sutures were measured using a thread and a graduated scale. The mean length of the coronal suture was significantly higher in males (24.8 ± 1.4 cm) than in females (22.7 ± 1.4 cm). The mean length of the sagittal suture was significantly higher in males (11.9±1.6 cm) than in females (10.8±1.6 cm). This study used the lengths of the coronal and sagittal sutures as measurements for sex estimation for the first time. Receiver operator characteristic (ROC) curve analysis revealed that the combined coronal and sagittal sutures lengths were the best sex discriminator (AUC= 0.859), followed by the coronal suture length (AUC= 0.855), and sagittal suture length (AUC= 0.697). Moreover, regression analysis was performed for sex determination; the highest accuracy was obtained by an equation that included the lengths of the coronal and sagittal sutures together (76%); followed by the coronal suture length (75%); then the sagittal suture length (71%). These measurements are easily obtained during a conventional autopsy and this method of sex estimation is cost effective when compared to radiological and DNA analysis. Moreover, the measurements can be carried out on dry skulls as long as the vault has identifiable landmarks.

The Effectiveness of Mini Primer STR CODIS in DNA Degradation as the Effect of High-Temperature Exposure

Background

More and more today, forensic identification through deoxyribonucleic acid (DNA) examination has achieved greater recognition in supporting Indonesia's law enforcement. Such examination is to determine the origin of a child, paternity cases, genealogical relation, or identifying unknown crime victims. However, along with the development of this DNA material examination, problems arise. DNA undergoes a degradation, commonly known as degraded DNA, which is one of the serious issues frequently encountered by forensic and DNA experts. Some forensic DNA experts take one of the alternatives to overcome this issue by implementing a mini primer set that is through a method to reduce the size of STR assays on DNA core locus examination.

Methods

In this study, the writers conduct research using the mini primers of CSF1PO, FGA, and D21S11 of the molar teeth exposed to 500°C temperature for 20 and 30 minutes and 750°C for the same amount of time.

Result

The findings show the DNA contents of molar teeth significantly (p < 0.05) decreased as the effect of high-temperature exposure. PCR result visualization shows CSF1PO is the only locus detected with mini primer exposed to 750°C temperature for 30 minutes (the highest exposure during this research).

Conclusions

This finding suggests that this locus is potential in examining identification through DNA analysis, especially on a degraded condition as the effect of high-temperature exposure. Besides, this could accelerate the identification process especially on mass disaster events or criminal cases.

Human identification: a review of methods employed within an Australian coronial death investigation system

Whilst many identification methods have been widely described and discussed in the literature, and considered in disaster and humanitarian contexts, there has been limited reporting and evaluation of the identification methods used in domestic medico-legal death investigation contexts. The aim of this study was to evaluate the identification methods utilised at the Victorian Institute of Forensic Medicine (VIFM), which forms part of a coronial medico-legal death investigation system. The method of identification and time taken to complete the identification were reviewed for all cases admitted to the VIFM over a five-year period from 1 July 2015 to 30 June 2020. The majority, 91%, of individuals admitted to the VIFM were visually identified. The remaining 9% of cases required identification by primary methods (i.e. fingerprints, DNA or dental) or, when those methods were not possible, by secondary methods (i.e. circumstantial). Visual identifications were the timeliest, taking an average of 1.5 days, whilst primary identification methods required an average of 5 days to complete. The triaging of identification methods, dependent on the case context, body preservation, availability of ante-mortem data, legal requirements and admissibility of the method, are determined by identification coordinators within the Human Identification Service (HIS) to ensure the most appropriate and timely method is employed. This review of human identification methods provides the foundation for future analyses to compare workflow processes and improve identification methods utilised in domestic medico-legal contexts.

A systematic investigation of human DNA preservation in medieval skeletons

Ancient DNA (aDNA) analyses necessitate the destructive sampling of archaeological material. Currently, the cochlea, part of the osseous inner ear located inside the petrous pyramid, is the most sought after skeletal element for molecular analyses of ancient humans as it has been shown to yield high amounts of endogenous DNA. However, destructive sampling of the petrous pyramid may not always be possible, particularly in cases where preservation of skeletal morphology is of top priority. To investigate alternatives, we present a survey of human aDNA preservation for each of ten skeletal elements in a skeletal collection from Medieval Germany. Through comparison of human DNA content and quality we confirm best performance of the petrous pyramid and identify seven additional sampling locations across four skeletal elements that yield adequate aDNA for most applications in human palaeogenetics. Our study provides a better perspective on DNA preservation across the human skeleton and takes a further step toward the more responsible use of ancient materials in human aDNA studies.