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Sacco MA, Gualtieri S, Tarallo AP, Calanna L, La Russa R, Aquila I. The Role of Molecular Investigations in Estimating the Time since Deposition (TSD) of Bloodstains: A Systematic Review of the Literature. Int J Mol Sci 2024; 25:7469. [PMID: 39000576 PMCID: PMC11242220 DOI: 10.3390/ijms25137469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/05/2024] [Accepted: 07/05/2024] [Indexed: 07/16/2024] Open
Abstract
At many crime scenes, investigators are able to trace and find traces of blood. For many years, it was believed that such traces could only be subjected to genetic investigations, such as those aimed at comparing DNA profiling with a suspect to verify his identity, and that it was therefore not possible to backdate the traces. In recent years, various works have used experimental models to investigate the possibility of identifying markers and methodologies for estimating the time since deposition (TSD) of bloodstains. Despite the results, these methods are still not part of standard procedures, and there is no univocal analysis methodology. In this work we carried out a systematic literature review of all the papers published in the last ten years on this topic, comparing the experimental models created. This review demonstrates the potential that different molecular approaches, such as transcriptomics, metabolomics, proteomics, and spectrometry, can have in the analysis of TSD, with notable sensitivity and specificity. This paper also analyzes the intrinsic and extrinsic limits of these models and emphasizes the need to continue research work on this topic, considering the importance that this parameter can assume in forensic investigations against a suspect.
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Affiliation(s)
- Matteo Antonio Sacco
- Institute of Legal Medicine, Department of Medical and Surgical Sciences, “Magna Graecia” University, 88100 Catanzaro, Italy; (M.A.S.); (S.G.); (A.P.T.); (L.C.)
| | - Saverio Gualtieri
- Institute of Legal Medicine, Department of Medical and Surgical Sciences, “Magna Graecia” University, 88100 Catanzaro, Italy; (M.A.S.); (S.G.); (A.P.T.); (L.C.)
| | - Alessandro Pasquale Tarallo
- Institute of Legal Medicine, Department of Medical and Surgical Sciences, “Magna Graecia” University, 88100 Catanzaro, Italy; (M.A.S.); (S.G.); (A.P.T.); (L.C.)
| | - Luca Calanna
- Institute of Legal Medicine, Department of Medical and Surgical Sciences, “Magna Graecia” University, 88100 Catanzaro, Italy; (M.A.S.); (S.G.); (A.P.T.); (L.C.)
| | - Raffaele La Russa
- Department of Clinical Medicine, Public Health, Life Sciences, and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
| | - Isabella Aquila
- Institute of Legal Medicine, Department of Medical and Surgical Sciences, “Magna Graecia” University, 88100 Catanzaro, Italy; (M.A.S.); (S.G.); (A.P.T.); (L.C.)
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Weber A, Wójtowicz A, Wietecha-Posłuszny R, Lednev IK. Raman Spectroscopy for the Time since Deposition Estimation of a Menstrual Bloodstain. SENSORS (BASEL, SWITZERLAND) 2024; 24:3262. [PMID: 38894054 PMCID: PMC11174499 DOI: 10.3390/s24113262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 06/21/2024]
Abstract
Forensic chemistry plays a crucial role in aiding law enforcement investigations by applying analytical techniques for the analysis of evidence. While bloodstains are frequently encountered at crime scenes, distinguishing between peripheral and menstrual bloodstains presents a challenge. This is due to their similar appearance post-drying. Raman spectroscopy has emerged as a promising technique capable of discriminating between the two types of bloodstains, offering invaluable probative information. Moreover, estimating the time since deposition (TSD) of bloodstains aids in crime scene reconstruction and prioritizing what evidence to collect. Despite extensive research focusing on TSD estimations, primarily in peripheral bloodstains, a crucial gap exists in determining the TSD of menstrual bloodstains. This study demonstrates how Raman spectroscopy effectively analyzes biological samples like menstrual blood, showing similar aging patterns to those of peripheral blood and provides proof-of-concept models for determining the TSD of menstrual blood. While this work shows promising results for creating a universal model for bloodstain age determination, further testing with more donors needs to be conducted before the implementation of this method into forensic practice.
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Affiliation(s)
- Alexis Weber
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA;
| | - Anna Wójtowicz
- Laboratory for Forensic Chemistry, Department of Analytical Chemistry, Faculty of Chemistry, Jagiellonian University, 2 Gronostajowa St., 30-387 Kraków, Poland; (A.W.); (R.W.-P.)
| | - Renata Wietecha-Posłuszny
- Laboratory for Forensic Chemistry, Department of Analytical Chemistry, Faculty of Chemistry, Jagiellonian University, 2 Gronostajowa St., 30-387 Kraków, Poland; (A.W.); (R.W.-P.)
| | - Igor K. Lednev
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA;
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Tastekin B, Akcan R, Evran E, Tamer U, Zengin HY, Yildirim MS, Boyaci IH. Estimation of time since deposition of semen stain on different fabric types using ATR-FTIR spectroscopy and chemometrics. Forensic Sci Int 2024; 354:111885. [PMID: 38007869 DOI: 10.1016/j.forsciint.2023.111885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/18/2023] [Accepted: 11/07/2023] [Indexed: 11/28/2023]
Abstract
Various body fluids such as blood, semen, vaginal secretions, and saliva are frequently encountered at crime scene. In cases of sexual assault, semen stains are one of the most reliable evidence of biological origin. In this study, our objective was to develop a method for estimating the time since deposition of semen stains on five different fabric types using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy, with a focus on a time frame of up to 8 weeks. Semen samples from six different volunteers were dripped onto five distinct fabric materials, and ATR-FTIR measurements were obtained at 17 different time points. Principal component analysis (PCA) and partial least squares (PLS) methods were employed to differentiate semen stains on various fabric samples and estimate the age of semen stains. Models constructed using PCA and PLSR achieved high R2 values and low root-mean-square error (RMSE). While the performance varies depending on fabric types, it was observed that age estimation of semen stains can be made within following intervals: 0.39-0.76 days for 0-7 day range, 2.59-3.38 days for the 1-8 week range, and 3.98-8.1 days for the 0-56 day range. This study demonstrates the effectiveness of using ATR-FTIR spectroscopy in combination with chemometrics to estimate the age of human semen stains on various fabric types based on time-dependent spectral changes.
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Affiliation(s)
- Burak Tastekin
- Department of Forensic Medicine, Hacettepe University, Ankara, Turkey.
| | - Ramazan Akcan
- Department of Forensic Medicine, Hacettepe University, Ankara, Turkey.
| | - Eylul Evran
- Department of Food Engineering, Hacettepe University, Ankara, Turkey.
| | - Ugur Tamer
- Department of Analytical Chemistry, Gazi University, Ankara, Turkey.
| | - H Yagmur Zengin
- Department of Biostatistics, Hacettepe University, Ankara, Turkey.
| | - Mahmut Serif Yildirim
- Department of Forensic Medicine, Afyonkarahisar Health Sciences University, Afyonkarahisar, Turkey.
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Alkhuder K. Attenuated total reflection-Fourier transform infrared spectroscopy: a universal analytical technique with promising applications in forensic analyses. Int J Legal Med 2022; 136:1717-1736. [PMID: 36050421 PMCID: PMC9436726 DOI: 10.1007/s00414-022-02882-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022]
Abstract
Contemporary criminal investigations are based on the statements made by the victim and the eyewitnesses. They also rely on the physical evidences found in the crime scene. These evidences, and more particularly biological ones, have a great judicial value in the courtroom. They are usually used to revoke the suspect's allegations and confirm or refute the statements made by the victim and the witnesses. Stains of body fluids are biological evidences highly sought by forensic investigators. In many criminal cases, the success of the investigation relies on the correct identification and classification of these stains. Therefore, the adoption of reliable and accurate forensic analytical methods seems to be of vital importance to attain this objective. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a modern and universal analytical technique capable of fingerprint recognition of the analyte using minimal amount of the test sample. The current systematic review aims to through light on the fundamentals of this technique and to illustrate its wide range of applications in forensic investigations. ATR-FTIR is a nondestructive technique which has demonstrated an exceptional efficiency in detecting, identifying and discriminating between stains of various types of body fluids usually encountered in crime scenes. The ATR-FTIR spectral data generated from bloodstains can be used to deduce a wealth of information related to the donor species, age, gender, and race. These data can also be exploited to discriminate between stains of different types of bloods including menstrual and peripheral bloods. In addition, ATR-FTIR has a great utility in the postmortem investigations. More particularly, in estimating the postmortem interval and diagnosing death caused by extreme weather conditions. It is also useful in diagnosing some ambiguous death causes such as fatal anaphylactic shock and diabetic ketoacidosis.
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Affiliation(s)
- Khaled Alkhuder
- Division of Microbial Disease, UCL Eastman Dental Institute, University College London, 256 Gray's Inn Road, London, WC1X 8LD, UK.
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Wang G, Cai W, Wu H, Yang C, Yu K, Liu R, Wei X, Lin H, Sun Q, Wang Z. Identification of human and non-human bloodstains on rough carriers based on ATR-FTIR and chemometrics. Microchem J 2022. [DOI: 10.1016/j.microc.2022.107620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sharma S, Chophi R, Jossan JK, Singh R. Detection of bloodstains using attenuated total reflectance-Fourier transform infrared spectroscopy supported with PCA and PCA-LDA. MEDICINE, SCIENCE, AND THE LAW 2021; 61:292-301. [PMID: 33926284 DOI: 10.1177/00258024211010926] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The most important task in a criminal investigation is to detect and identify the recovered biological stains beyond reasonable scientific doubt and preserve the sample for further DNA analysis. In the light of this fact, many presumptive and confirmatory tests are routinely employed in the forensic laboratories to determine the type of body fluid. However, the currently used techniques are specific to one type of body fluid and hence it cannot be utilized to differentiate multiple body fluids. Moreover, these tests consume the samples in due process, and thus it becomes a great limitation especially considering the fact that samples are recovered in minute quantity in forensic cases. Therefore, such limitations necessitate the use of non-destructive techniques that can be applied simultaneously to all types of bodily fluids and allow sample preservation for further analysis. In the current work, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy has been used to circumvent the aforementioned limitations. The important factors which could influence the detection of blood such as the effect of substrates, washing/chemical treatment, ageing, and dilution limits on the analysis of blood have been analysed. In addition, blood discrimination from non-blood substance (biological and non-biological in nature) has also been studied. Chemometric technique that is PCA-LDA has been used to discriminate blood from other body fluids and it resulted in 100% accurate classification. Furthermore, blood and non-blood substances including fake blood have also been classified into separate clusters with a 100% accuracy, sensitivity, and specificity. All-inclusive, this preliminary study substantiates the potential application of ATR-FTIR spectroscopy for the non-destructive identification of blood traces in simulated forensic casework conditions with 0% rate of false classification.
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Affiliation(s)
- Sweety Sharma
- Department of Forensic Science, 29766Punjabi University, Patiala, Punjab, India
| | - Rito Chophi
- Department of Forensic Science, 29766Punjabi University, Patiala, Punjab, India
| | | | - Rajinder Singh
- Department of Forensic Science, 29766Punjabi University, Patiala, Punjab, India
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Analysis of the ex-vivo transformation of semen, saliva and urine as they dry out using ATR-FTIR spectroscopy and chemometric approach. Sci Rep 2021; 11:11855. [PMID: 34088945 PMCID: PMC8178304 DOI: 10.1038/s41598-021-91009-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 05/19/2021] [Indexed: 11/08/2022] Open
Abstract
The ex-vivo biochemical changes of different body fluids also referred as aging of fluids are potential marker for the estimation of Time since deposition. Infrared spectroscopy has great potential to reveal the biochemical changes in these fluids as previously reported by several researchers. The present study is focused to analyze the spectral changes in the ATR-FTIR spectra of three body fluids, commonly encountered in violent crimes i.e., semen, saliva, and urine as they dry out. The whole analytical timeline is divided into relatively slow phase I due to the major contribution of water and faster Phase II due to significant evaporation of water. Two spectral regions i.e., 3200–3400 cm−1 and 1600–1000 cm−1 are the major contributors to the spectra of these fluids. Several peaks in the spectral region between 1600 and 1000 cm−1 showed highly significant regression equation with a higher coefficient of determination values in Phase II in contrary to the slow passing Phase I. Principal component and Partial Least Square Regression analysis are the two chemometric tool used to estimate the time since deposition of the aforesaid fluids as they dry out. Additionally, this study potentially estimates the time since deposition of an offense from the aging of the body fluids at the early stages after its occurrence as well as works as the precursor for further studies on an extended timeframe.
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Das T, Harshey A, Nigam K, Yadav VK, Srivastava A. Analytical approaches for bloodstain aging by vibrational spectroscopy: Current trends and future perspectives. Microchem J 2020. [DOI: 10.1016/j.microc.2020.105278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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A bench-top model of middle ear effusion diagnosed with optical tympanometry. Int J Pediatr Otorhinolaryngol 2020; 134:110054. [PMID: 32344235 PMCID: PMC7282940 DOI: 10.1016/j.ijporl.2020.110054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/16/2020] [Accepted: 04/16/2020] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To assess the validity of a bench-top model of an optical tympanometry device to diagnose in vitro model of middle ear effusion (MEE). METHODS AND MATERIALS We illuminated an in vitro model of ear canal and tympanic membrane with broadband light and relayed remitted light to a spectrometer system. We then used our proprietary algorithm to extract spectral features that, together with our logistic regression classifiers, led us to calculate a set of simplified indices related to different middle ear states. Our model included a glass vial covered with a porcine submucosa (representing the tympanic membrane) and filled with air, water, or milk solution (representing different MEE), and a set of cover-glass slips filled with either blood (representing erythema) or cerumen. By interchanging fluid types and cover-glass slips, we made measurements on combinations corresponding to normal healthy ear and purulent or serous MEE. RESULTS Each simulated condition had a distinct spectral profile, which was then employed by our algorithm to discriminate clean and cerumen-covered purulent and serous MEE. Two logistic purulent and serous MEE classifiers correctly classified all in vitro middle ear states with 100% accuracy assessed by leave-one-out and k-fold cross validation. CONCLUSIONS This proof-of-concept in vitro study addressed an unmet need by introducing a device that easily and accurately can assess middle ear effusion. Future in vivo studies aimed at collecting data from clinical settings are warranted to further elucidate the validity of the technology in diagnosing pediatric acute otitis media.
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Detection of vaginal fluid stains on common substrates via ATR FT-IR spectroscopy. Int J Legal Med 2020; 134:1591-1602. [DOI: 10.1007/s00414-020-02333-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/29/2020] [Indexed: 12/19/2022]
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Li H, Yang E, Zhang S, Zhang J, Yuan L, Liu R, Ullah S, Wang Q, Mushtaq N, Shi Y, An C, Wang Z, Xu J. Molecular characterization of gut microbial shift in SD rats after death for 30 days. Arch Microbiol 2020; 202:1763-1773. [PMID: 32350549 DOI: 10.1007/s00203-020-01889-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/26/2020] [Accepted: 04/15/2020] [Indexed: 01/06/2023]
Abstract
To observe the temporal shifts of the intestinal microbial community structure and diversity in rats for 30 days after death. Rectal swabs were collected from rats before death (BD) and on day 1, 5, 10, 15, 20, 25, and 30 after death (AD). Bacteria genomic DNA was extracted and V3 + V4 regions of 16S rRNA gene were amplified by PCR. The amplicons were sequenced at Illumina MiSeq sequencing platform. The bacterial diversity and richness showed similar results from day 1 to 5 and day 10 to 25 all presenting downtrend, while from day 5 to 10 showed slightly increased. The relative abundance of Firmicutes and Proteobacteria displayed inverse variation in day 1, 5, 10 and that was the former decreased, the latter increased. Bacteroidetes, Spirochaete and TM7 in day 15, 20, 25, 30 was significantly decline comparing with BD. Enterococcus and Proteus displayed reduced trend over day 1, 5, 10 and day 10, 15, 20, 25, respectively, while Sporosarcina showed obvious elevation during day 15, 20, 25. Accordingly, there was a certain correlation between intestinal flora succession and the time of death. The results suggested that intestinal flora may be potential indicator to aid estimation of post-mortem interval (PMI).
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Affiliation(s)
- Huan Li
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - E Yang
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Siruo Zhang
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Jing Zhang
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Lu Yuan
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Ruina Liu
- College of Forensic Medicine, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Shakir Ullah
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Qi Wang
- College of Forensic Medicine, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China.,Teaching and Research Section of Forensic Medicine, College of Basic Medicine, Chongqing Medical University, Chongqing, 400016, People's Republic of China
| | - Nosheen Mushtaq
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
| | - Yi Shi
- Shaanxi Provincial Centre for Disease Control and Prevention, Xi'an, People's Republic of China
| | - Cuihong An
- Shaanxi Provincial Centre for Disease Control and Prevention, Xi'an, People's Republic of China
| | - Zhenyuan Wang
- College of Forensic Medicine, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China.
| | - Jiru Xu
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China.
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Sharma S, Singh R. Detection and discrimination of seminal fluid using attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy combined with chemometrics. Int J Legal Med 2019; 134:411-432. [PMID: 31814056 DOI: 10.1007/s00414-019-02222-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 11/27/2019] [Indexed: 12/31/2022]
Abstract
Semen is most frequently encountered body fluid in forensic cases apart from blood especially in sexual assault cases. The presence and absence of semen can help in conviction or exoneration of a suspect by either confirming or refuting the claims put forward by the suspect and the victim. However, in the wake of limited studies on non-destructive and rapid analysis of semen, it is fairly difficult. Therefore, it is an increasing demand to pioneer the application of available analytical methods in such manner that non-destructive, automated, rapid, and reliable identification and discrimination of body fluids can be established. In the present study, such a methodological application of attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy has been put forward as one of the initial steps towards the identification and discrimination/classification of seminal fluid from vaginal fluid and other human biological as well as non-biological look-alike semen substances using chemometric tools which are principal component analysis (PCA), partial least square regression (PLSR), and linear discriminant analysis (LDA). Effect of other simulated factors such as substrate interference, mixing with other body fluids, dilutions, and washing and chemical treatments to the samples has been studied. PCA resulted in 98.8% of accuracy for the discrimination of seminal fluid from vaginal fluid whilst 100% accuracy was obtained using LDA method. One hundred percent discrimination was achieved to discriminate semen from other biological fluids using PLSR and LDA, and from non-biological substances using PCA-LDA models. Furthermore, results of the effect of substrates, chemical treatment, mixing with vaginal secretions, and dilution have also been described.
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Affiliation(s)
- Sweety Sharma
- Department of Forensic Science, Punjabi University, Patiala, Punjab, 147002, India
| | - Rajinder Singh
- Department of Forensic Science, Punjabi University, Patiala, Punjab, 147002, India.
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13
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Zha S, Wei X, Fang R, Wang Q, Lin H, Zhang K, Zhang H, Liu R, Li Z, Huang P, Wang Z. Estimation of the age of human semen stains by attenuated total reflection Fourier transform infrared spectroscopy: a preliminary study. Forensic Sci Res 2019; 5:119-125. [PMID: 32939428 PMCID: PMC7476623 DOI: 10.1080/20961790.2019.1642567] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 01/28/2023] Open
Abstract
Semen stain is one of the most important biological evidence at sexual crime scenes. Age estimation of human semen stains plays an important role in forensic work, and it is rarely studied due to lack of well-established methods. In this study, the technique called attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) coupled with advanced chemometric methods was employed to determine the age of semen stains on three different substrates: glass slides, tissues and fabric made of regenerated cellulose fibres up to 6 d. Partial least squares regression (PLSR) was used in conjunction with spectral analysis for age estimation, and the results generated high R2 values (cross-validation: 0.81, external validation: 0.74) but a narrow margin of error for root mean square error (RMSE) (RMSE of cross-validation: 0.77 d, RMSE of prediction: 1.02 d). Additionally, our results indicated the robustness of PLSR model was not weaken by the influence of different substrates in this study. Our results indicate that ATR-FTIR, combined with chemometric methods, shows great potential as a convenient and efficient tool for age estimation of semen stains. Moreover, the method could be applied to routine forensic investigations in the future.
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Affiliation(s)
- Shuai Zha
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Xin Wei
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Ruoxi Fang
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Qi Wang
- Department of Forensic Medicine, Chongqing Medical University, Chongqing, China
| | - Hancheng Lin
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Kai Zhang
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Haohui Zhang
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Ruina Liu
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Zhouru Li
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, China
| | - Ping Huang
- Department of Forensic Pathology, Academy of Forensic Science, Shanghai, China
| | - Zhenyuan Wang
- Department of Forensic Pathology, Xi'an Jiaotong University School of Medicine, Xi'an, China
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14
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Sharma S, Chophi R, Singh R. Forensic discrimination of menstrual blood and peripheral blood using attenuated total reflectance (ATR)-Fourier transform infrared (FT-IR) spectroscopy and chemometrics. Int J Legal Med 2019; 134:63-77. [PMID: 31388794 DOI: 10.1007/s00414-019-02134-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 07/26/2019] [Indexed: 02/07/2023]
Abstract
Body fluids are one of the most important pieces of evidence encountered in forensic cases especially in cases of sexual assault. Analysis of such evidence can help to establish a link between the perpetrator, the victim, and the crime scene and thereby assist in crime reconstruction. However, one of the biggest challenges faced by the investigators in sexual assault cases is that of ascertaining the issue of consent of the victim. In this matter, differentiation of menstrual blood (either in dried or stained form) from traumatic peripheral blood can give a potential solution on this particular aspect. A number of studies have been attempted to differentiate these two body fluids using various biochemical and serological methods. However, the methods employed are limited by factors such as sample destructivity and non-specificity, and the methods are susceptible to false positive results. In the present study, the scope of attenuated total reflectance (ATR)-Fourier transform infrared (FT-IR) spectroscopy in discriminating samples of menstrual blood and peripheral blood has been investigated, in combination with chemometric tools such as principal component analysis (PCA), partial least square regression (PLSR), and linear discriminant analysis (LDA). PCA resulted in 93.3% accuracy, whereas PLSR and LDA resulted in 100% accuracy for the discrimination of peripheral blood from menstrual blood. Application of PCA for the discrimination of menstrual blood from vaginal fluid and seminal fluid delivered 100% classification. Similarly, 100% classification was achieved while differentiating between menstrual blood and blood look-alike substances. Furthermore, in the current study, the effect of substrates on the analysis of menstrual blood has also been studied and described. Graphical Abstract.
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Affiliation(s)
- Sweety Sharma
- Department of Forensic Science, Punjabi University, Patiala, Punjab, 147002, India
| | - Rito Chophi
- Department of Forensic Science, Punjabi University, Patiala, Punjab, 147002, India
| | - Rajinder Singh
- Department of Forensic Science, Punjabi University, Patiala, Punjab, 147002, India.
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