Rapid DNA analysis for automated processing and interpretation of low DNA content samples

Processing biological samples from simulated radiological terrorist events using Rapid DNA instruments

Two commercially available portable Rapid DNA instruments were evaluated for their ability to process 1 µL and 10 µL saliva samples deposited on metal and plastic surfaces and contaminated with surrogates of cesium (Cs)-137, strontium (Sr)-90 and cobalt (Co)-60; radioactive materials potentially released during a nuclear weapon accident or a radiological dispersal device detonation. A comparable success rate was noted for both Rapid DNA instruments when considering the number of complete and balanced DNA profiles, the number of profiles with a minimum of 10 autosomal STR loci (out of 23 [FlexPlex™ 27] or 21 [GlobalFiler™ Express]), and the possibility to search a national DNA database in Canada and the United States. Cobalt had an adverse impact on the quality of the megaplex short tandem repeat (STR) DNA profiles derived on each instrument for two of the three contamination levels tested in this study, i.e., 0.05 M and 0.1 M as reflected by a reduced number of detected alleles and decreased profile peak heights. Strontium exhibited some adverse effect on the Rapid DNA results when used at the highest contamination level (0.1 M) whereas cesium had none. No new artifacts were observed in the Rapid DNA profiles of samples spiked with the non-radiogenic surrogates. Importantly, in the context of a radiological/nuclear (RN) event, the ANDE™ 6C offers the possibility to dispose of all radioactive materials associated with contaminated samples quickly using a chip on which all steps of the Rapid DNA process are performed whereas the RapidHIT™ ID accumulates radioactive materials for many days before disposal. An individual handling 25 samples in a week (5 per day) on the RapidHIT™ ID at a 30.5 cm distance with a 5 min exposure to the radioactive source estimated at every run would exceed the 0.042 µSv/5 min limit with gamma dose rates for Cs at 0.13 mSv and for Co at 3.8 mSv. Beta dose rates calculated for the surrogate isotopes at the three concentrations tested were also above the recommended radiation exposure limit of 1 mSv/yr (0.042 µSv/5 min). Various potential mechanisms of action behind the interference noted for Sr and Co at high concentrations are presented. These elements may play a role in the steps prior to PCR (at the DNA molecule by binding to bases or to phosphate groups), during PCR (at the DNA polymerase as cofactors for catalytic sites), or even during amplified DNA fragment detection (as fluorescence quenchers).

Comparative analysis of two Rapid DNA technologies for the processing of blood and saliva-based samples

Rapid DNA technologies recently gained significant momentum as a means to generate DNA profiles faster than with standard laboratory workflows. Initially developed for the analysis of buccal reference samples, applications are being considered for other types of forensic samples. In this study, an identical set of 150 blood and saliva-based samples was processed using two different Rapid DNA technologies, the Applied BioSystems™ RapidHIT™ ID System using the RapidINTEL™ sample cartridge and the ANDE™ 6C Rapid DNA Analysis™ System using the I-Chip. A subset of samples were subjected to alternative collection methods or sample pre-treatments to determine the optimal strategy for each instrument. An equivalent sample set was also processed using a conventional DNA analysis workflow. The sensitivity range of the two Rapid DNA technologies was comparable based on blood and saliva dilution series, with both technologies able to generate full profiles from samples typically yielding 5-10 ng of DNA when processed using conventional DNA analysis. The brand of cotton swabs used for Rapid DNA analysis had an impact on the results for both systems. Differences were observed in success rate between the two systems when processing blood (on fabrics, FTA paper or hard surfaces) and saliva-based samples (drink containers, FTA paper, chewing gum, cigarette butt filter paper) and depended on the sample type. Importantly, deviating from the manufacturer's instructions for sample collection and pre-treatment was more detrimental to the ANDE 6C results. The quality of DNA profiles, as assessed using heterozygote peak height ratios, interloci balance and artifact presence, confirmed the results to be reliable and acceptable for single source samples. Profiling results were obtained when samples were reprocessed using the same Rapid DNA technology or conventional DNA analysis. Secondary analysis using a substitute software (GeneMapper ID-X v1.5) to recover additional genetic information was shown to be feasible. Finally, a comparison between the Applied Biosystems™ RapidHIT™ ID System Software v1.3.1 and v1.3.2 was also performed. Findings of this study could assist those interested in using Rapid DNA technology for blood or saliva-based samples, in various settings and for different applications.

Comparative study of Rapid DNA versus conventional methods on compromised bones

Equivalent amounts of compromised bones were used to directly compare STR success of conventional and Rapid DNA methods. Conventional DNA extraction methods, including manual full demineralization and semi-automated PrepFiler BTA/ AutoMate Express (ThermoFisher Scientific), provided insights regarding the DNA quantity and extent of degradation of each compromised bone analyzed with ANDE 6C (ANDE Corp) and RapidHIT ID (ThermoFisher Scientific) Rapid systems. Full demineralization provided higher DNA yields than extraction with the AutoMate Express for quality control (QC) and environmentally challenged bones. The degradation indices ranged from ∼1.8 to 73. Both demineralization and AutoMate Express extracts benefited from additional clean-up with NucleoSpin XS devices, which usually resulted in more alleles being detected than without further clean-up. Complete "CODIS 20″ profiles could be obtained with bone QC1 with all methods. However, among the 14 compromised bones with low DNA content, complete CODIS 20 profiles were detected for 7, 4, and 0 bones analyzed with demineralization, AutoMate Express and ANDE methods, respectively. The RapidHIT ID was the least sensitive method, providing the fewest detectable alleles for the bones tested. Whereas extracted DNA of approximately 0.1 ng can yield complete GlobalFiler STR profiles, at least 30 ng was required for complete FlexPlex 27 profiles using the ANDE 6C Rapid DNA system. In addition to being less sensitive than conventional methods, the tested Rapid DNA approaches were less predictable when attempting to improve STR success and proved to be less reliable in genotyping accuracy.

A Systematic Review on Commercially Available Integrated Systems for Forensic DNA Analysis

This systematic review describes and discusses three commercially available integrated systems for forensic DNA analysis, i.e., ParaDNA, RapidHIT, and ANDE. A variety of aspects, such as performance, time-to-result, ease-of-use, portability, and costs (per analysis run) of these three (modified) rapid DNA analysis systems, are considered. Despite their advantages and developmental progress, major steps still have to be made before rapid systems can be broadly applied at crime scenes for full DNA profiling. Aspects in particular that need (further) improvement are portability, performance, the possibility to analyze a (wider) variety of (complex) forensic samples, and (cartridge) costs. Moreover, steps forward regarding ease-of-use and time-to-result will benefit the broader use of commercial rapid DNA systems. In fact, it would be a profit if rapid DNA systems could be used for full DNA profile generation as well as indicative analyses that can give direction to forensic investigators which will speed up investigations.

Review of direct PCR and Rapid DNA approaches to streamline sexual assault kit testing

Crime laboratories have been faced with large casework backlogs due to lengthy processing times, limited resources and scientists, and rising crime rates. Evidence related to sexual assault crimes, specifically sexual assault kits (SAKs), heavily contribute to the reported backlogs. Although more sensitive, faster chemistries and automated techniques have been implemented over the years, the traditional STR workflow remains relatively unchanged. Enhanced workflows such as direct PCR and Rapid DNA have the potential to streamline the processing of forensic evidence items including those commonly submitted in SAKs, but the FBI QAS guidelines restrict CODIS-approved labs from implementing these methods for forensic samples. Recent studies have shown decreased turnaround times and improved or comparable profiling success with both approaches. However, review of the literature shows a lack of in-depth research comparing traditional DNA workflows to faster and more sensitive direct PCR and/or Rapid DNA approaches for evidentiary samples, especially for SAKs. By providing the forensic science and criminal justice communities with the strengths and limitations of direct PCR and Rapid DNA methods, stakeholders and policy makers may be better informed.

Validation of the Applied Biosystems RapidHIT ID instrument and ACE GlobalFiler Express sample cartridge

Rapid DNA platforms are fully automated systems capable of processing DNA from biological samples and interpreting the results in approximately 90 minutes with minimal human intervention. With a greater reliance on the system than on the analyst, validation data are especially needed to define the performance and limitations of commercially available Rapid DNA systems. Thus, validation studies of a Rapid DNA workflow consisting of the Applied Biosystems RapidHIT ID Instrument and RapidLINK software with a focus on the ACE GlobalFiler Express Sample Cartridge and reference buccal swabs were performed in accordance with Scientific Working Group on DNA Analysis Methods Validation Guidelines. These validation studies included assessments of sensitivity, contamination, concordance, reproducibility and repeatability, stability, inhibition, mixtures, sample reprocessing, precision, and first-pass success rate. Overall, the current Applied Biosystems RapidHIT ID Instrument with the ACE GlobalFiler Express sample cartridge was found to be a reliable tool for generation of STR profiles from reference-type buccal swabs.

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.

The 2018 California Wildfires: Integration of Rapid DNA to Dramatically Accelerate Victim Identification

In November 2018, Butte County, California, was decimated by the Camp Fire, the deadliest wildfire in state history. Over 150,000 acres were destroyed, and at its peak, the fire consumed eighty acres per minute. The speed and intensity of the oncoming flames killed scores of people, and weeks before the fire was contained, first responders began searching through the rubble of 18,804 residences and commercial buildings. As with most mass disasters, conventional identification modalities (e.g., fingerprints, odontology, hardware) were utilized to identify victims. The intensity and duration of the fire severely degraded most of the remains, and these approaches were useful in only 22 of 84 cases. In the past, the remaining cases would have been subjected to conventional DNA analysis, which may have required months to years. Instead, Rapid DNA technology was utilized (in a rented recreational vehicle outside the Sacramento morgue) in the victim identification effort. Sixty-nine sets of remains were subjected to Rapid DNA Identification and, of these, 62 (89.9%) generated short tandem repeat profiles that were subjected to familial searching; essentially all these profiles were produced within hours of sample receipt. Samples successfully utilized for DNA identification included blood, bone, liver, muscle, soft tissue of unknown origin, and brain. In tandem with processing of 255 family reference samples, 58 victims were identified. This work represents the first use of Rapid DNA Identification in a mass casualty event, and the results support the use of Rapid DNA as an integrated tool with conventional disaster victim identification modalities.

Interpol review of forensic biology and forensic DNA typing 2016-2019

This review paper covers the forensic-relevant literature in biological sciences from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Developmental Validation of the ANDE 6C System for Rapid DNA Analysis of Forensic Casework and DVI Samples

A developmental validation was performed to demonstrate reliability, reproducibility, and robustness of the ANDE Rapid DNA Identification System for processing of crime scene and disaster victim identification (DVI) samples. A total of 1705 samples were evaluated, including blood, oral epithelial samples from drinking containers, samples on FTA and untreated paper, semen, bone, and soft tissues. This study was conducted to address the FBI’s Quality Assurance Standards on developmental validation and to accumulate data from a sufficient number of unique donors and sample types to meet NDIS submission requirements for acceptance of the ANDE Expert System for casework use. To date, no Expert System has been approved for such samples, but the results of this study demonstrated that the automated Expert System performs similarly to conventional laboratory data analysis. Furthermore, Rapid DNA analysis demonstrated accuracy, precision, resolution, concordance, and reproducibility that were comparable to conventional processing along with appropriate species specificity, limit of detection, performance in the presence of inhibitors. No lane‐to‐lane or run‐to‐run contamination was observed, and the system correctly identified the presence of mixtures. Taken together, the ANDE instrument, I‐Chip consumable, FlexPlex chemistry (a 27‐locus STR assay compatible with all widely used global loci, including the CODIS core 20 loci), and automated Expert System successfully processed and interpreted more than 1200 unique samples with over 99.99% concordant CODIS alleles. This extensive developmental validation data provides support for broad use of the system by agencies and accredited forensic laboratories in single‐source suspect‐evidence comparisons, local database searches, and DVI.

Identification of human remains using Rapid DNA analysis

Rapid identification of human remains following mass casualty events is essential to bring closure to family members and friends of the victims. Unfortunately, disaster victim identification, missing persons identification, and forensic casework analysis are often complicated by sample degradation due to exposure to harsh environmental conditions. Following a mass disaster, forensic laboratories may be overwhelmed by the number of dissociated portions that require identification and reassociation or compromised by the event itself. The interval between the disaster and receipt of victim samples at a laboratory is critical in that sample quality deteriorates as the postmortem interval increases. When bodies decompose due to delay in collection, transport, and sample processing, DNA becomes progressively fragmented, adversely impacting identification. We have previously developed a fully automated, field-forward Rapid DNA identification system that produces STR profiles (also referred to as DNA IDs or DNA fingerprints) from buccal and crime scene samples. The system performs all sample processing and data interpretation in less than 2 h. Here, we present results on Rapid DNA identification performed on several tissue types (including buccal, muscle, liver, brain, tooth, and bone) from exposed human bodies placed above ground or stored in a morgue/cooler, two scenarios commonly encountered following mass disasters. We demonstrate that for exposed remains, buccal swabs are the sample of choice for up to 11 days exposure and bone and tooth samples generated excellent DNA IDs for the 1-year duration of the study. For refrigerated remains, all sample types generated excellent DNA IDs for the 3-month testing period.

Modular-Based Integrated Microsystem with Multiple Sample Preparation Modules for Automated Forensic DNA Typing from Reference to Challenging Samples

The realization of an automated short tandem repeat (STR) analysis for forensic investigations is facing a unique challenge, that is DNA evidence with wide disparities in sample types, quality, and quantity. We developed a fully integrated microsystem in a modular-based architecture to accept and process various forensic samples in a "sample-in-answer-out" manner for forensic STR analysis. Two sample preparation modules (SPMs), the direct and the extraction SPM, were designed to be easily assembled with a capillary array electrophoresis (CAE) chip using a chip cartridge to efficiently achieve an adequate performance to different samples at a low cost. The direct SPM processed buccal swabs to produce STR profiles without DNA extraction in about 2 h. The extraction SPM analyzed more challenging blood samples based on chitosan-modified quartz filter paper for DNA extraction. This newly developed quartz filter provided a 90% DNA extraction efficiency and the "in situ" PCR capability, which enabled DNA extraction and PCR performed within a single chamber with all the DNA concentrated in the filter. We demonstrated that minute amounts of blood (0.25 μL), highly diluted blood (0.5 μL blood in 1 mL buffer), and latent bloodstains (5-μL bloodstain on cloth washed with detergent) can be automatically analyzed using our microsystem, reliably producing full STR profiles with a 100% calling of all the alleles. This modular-based microsystem with the capability of analyzing a wide range of samples should be able to play an increasing role in both urgent situations and routine forensic investigations, dramatically extending the applications and utility of automated DNA typing.

Developmental validation of the ANDE™ rapid DNA system with FlexPlex™ assay for arrestee and reference buccal swab processing and database searching

A developmental validation was performed to demonstrate reliability, reproducibility and robustness of the ANDE System with the FlexPlex assay, including an integrated Expert System, across a number of laboratories and buccal sample variations. Previously, the related DNAscan™/ANDE 4C Rapid DNA System using the PowerPlex^®16 assay and integrated Expert System Software received NDIS approval in March 2016. The enhanced ANDE instrument, referred to as ANDE 6C, and the accompanying 6-dye, 27-locus STR assay, referred to as FlexPlex, have been developed to be compatible with all widely used global loci, including the expanded set of the CODIS core 20 loci. Six forensic and research laboratories participated in the FlexPlex Rapid DNA developmental validation experiments, testing a total of 2045 swabs, including those obtained from 1387 unique individuals. The goal of this extensive and comprehensive validation was to thoroughly evaluate and document the ANDE System and its internal Expert System to reliably genotype reference buccal swab samples in a manner compliant with the FBI's Quality Assurance Standards and the NDIS Operational Procedures. The ANDE System, including automated Expert System analysis, generated reproducible and concordant results for buccal swabs when testing various instruments at different laboratories by a number of different operators. When testing a number of non-human DNAs, including oral bacteria, the ANDE System and FlexPlex assay demonstrated limited cross-reactivity. Potential PCR inhibitors were evaluated as part of the validation and no inhibition was detected. Reproducible and concordant profiles were generated from buccal swab samples collected with a limit of detection appropriate for buccal swab collections from arrestees. The precision and resolution of the System met industry standards for detection of microvariants and single base resolution. The integrated Expert System appropriately demonstrated the ability to correctly pass or fail profiles for CODIS upload without human review. During this comprehensive developmental validation, the ANDE System successfully interpreted over 2000 samples tested with over 99.99% concordant alleles. The data package described herein led to the ANDE System with the FlexPlex assay receiving NDIS approval in June 2018.

A fully integrated microchip system for automated forensic short tandem repeat analysis

We have successfully developed an integrated microsystem that combines two plastic microchips for DNA extraction and PCR amplification with a glass capillary array electrophoresis chip together in a compact control and detection instrument for automated forensic short tandem repeat (STR) analysis. DNA extraction followed by an "in situ PCR" was conducted in a single reaction chamber of the microchip based on a filter paper-based extraction methodology. PCR products were then mixed with sizing standards by an injection electrode and injected into the electrophoresis chip for four-color confocal fluorescence detection. The entire STR analysis can be completed in about two hours without any human intervention. Since the 15-plex STR system has a more stringent requirement for PCR efficiency, we optimized the structure of the plastic DNA extraction and amplification chip, in which the reaction chamber was formed by sandwiching a hollow structure layer with two blank cover layers, to reduce the adsorption of PCR reagents to the surfaces. In addition, PCR additives, bovine serum albumin, poly(ethylene glycol), and more magnesium chloride were included into the on-chip multiplex STR system. The limit-of-detection study demonstrated that our microsystem was able to produce full 15-plex STR profiles from 3.75 ng standard K562 DNA. Buccal swab and whole blood samples were also successfully typed by our system, validating the feasibility of performing rapid DNA typing in a "sample-in-answer-out" manner for on-site forensic human identification.

DNA persistence of bite marks on food and its relevance for STR typing

In forensic DNA analysis, salivary traces at crime scenes are a promising way to identify a person. However, crime scenes are oftentimes investigated a while after the crime and recovered samples might have been degraded leading to poor PCR amplification. Probably due to decomposition and negative visual impression of spoiled food, bite mark samples make up only a small part of our casework routine. In this study, bite marks on apples and chocolate bars as well as on an inert surface (microscope slide) were stored up to 3 weeks indoors and outdoors during different seasons and analyzed for amylase activity and DNA quantity and quality. The results underlined the stability of human nuclear DNA not only on inert but also on biological surfaces and their forensic usefulness even when bite marks are stored 21 days under adverse but realistic conditions at a crime scene. Overall, amylase activity as well as DNA quantity decreased over time depending on storage environment with a certain inter- and intrapersonal variation. But amylase activity testing was not found to be an appropriate screening tool for further analysis. Apple bite marks resulted in generally higher DNA amounts than chocolate bars and microscope slides. Although mold reduced the DNA quantity, complete STR profiles could be analyzed. High air humidity and cold temperatures were found to act preservative on raw food with high water content but caused loss of information over time for smooth inert surfaces and hygroscopic foods like sweets. Many factors are involved in the stability of DNA in bite marks and its resulting quality and quantity available for an STR analysis. However, since there was a substantial proportion of informative STR profiles even from bite marks stored for 21 days, the results encourage the analysis of those even if their visual appearance seems unfavorable.

Rapid detection and strain typing of Chlamydia trachomatis using a highly multiplexed microfluidic PCR assay

Nucleic acid amplification tests (NAATs) are recommended by the CDC for detection of Chlamydia trachomatis (Ct) urogenital infections. Current commercial NAATs require technical expertise and sophisticated laboratory infrastructure, are time-consuming and expensive, and do not differentiate the lymphogranuloma venereum (LGV) strains that require a longer duration of treatment than non-LGV strains. The multiplexed microfluidic PCR-based assay presented in this work simultaneously interrogates 13 loci to detect Ct and identify LGV and non-LGV strain-types. Based on amplified fragment length polymorphisms, the assay differentiates LGV, ocular, urogenital, and proctocolitis clades, and also serovars L1, L2, and L3 within the LGV group. The assay was evaluated in a blinded fashion using 95 clinical swabs, with 76 previously reported as urogenital Ct-positive samples and typed by ompA genotyping and/or Multi-Locus Sequence Typing. Results of the 13-plex assay showed that 51 samples fell within urogenital clade 2 or 4, 24 samples showed both clade 2 and 4 signatures, indicating possible mixed infection, gene rearrangement, or inter-clade recombination, and one sample was a noninvasive trachoma biovar (either a clade 3 or 4). The remaining 19 blinded samples were correctly identified as LGV clade 1 (3), ocular clade 3 (4), or as negatives (12). To date, no NAAT assay can provide a point-of-care applicable turnaround time for Ct detection while identifying clinically significant Ct strain types to inform appropriate treatment. Coupled with rapid DNA processing of clinical swabs (approximately 60 minutes from swab-in to result-out), the assay has significant potential as a rapid POC diagnostic for Ct infections.

FlexPlex27-highly multiplexed rapid DNA identification for law enforcement, kinship, and military applications

Rapid DNA identification is the use of a rugged, field-deployable system to generate short tandem repeat (STR) profiles in law enforcement, military, immigration, and homeland security applications. A performance verification study was conducted on the ANDE Rapid DNA identification system using FlexPlex27, a highly multiplexed, 27 locus assay that generates data for the expanded CODIS core loci and all additional STR loci required for international databasing. The assay contains 23 autosomal loci (D1S1656, D2S1338, D2S441, D3S1358, D5S81, D6S1043, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, FGA, CSF1PO, Penta E, TH01, vWA, TPOX, and SE33), three Y-chromosomal loci (DYS391, DYS576, and DYS570), and Amelogenin. Study results demonstrate that the instrument is reliable, reproducible, accurate, robust, and ready for a large scale, comprehensive developmental validation by NDIS-participating laboratories. The additional loci in the FlexPlex assay allow for improved STR profile sharing globally, increase the power of discrimination for identification matches, and improve the effectiveness of kinship analyses.

Electrode Materials in Microfluidic Systems for the Processing and Separation of DNA: A Mini Review

Since the advent of genetic analysis, electrode materials have played an irreplaceable role due to the easily-exploitable negatively-charged backbone of the DNA structure. Initially, the employment of electrophoretic movement lay only in the separation of DNA fragments of differing length; however, the widening utility of electrokinetic phenomena at the microscale in areas such as fluid transportation and multistep integration led researchers to capitalize further when translating processes to microfluidic or “lab-on-chip” devices. Over the following three decades, the field witnessed a plethora of ways in which the necessary voltages could be transmitted to the sample and reagents with many successes; however, additional demands were then placed on those hoping to bring their microdevices to the market place. A greater emphasis on the cost of all constituent parts along with the increased importance that fluidics be contained hermetically at all times meant groups would become more imaginative when incorporating electrode materials. This review will aim to exactly describe the evolution of how those materials have been employed in DNA-based microfluidic devices. It will focus on how developers began to explore other emerging uses and also discuss how their tactics reflected the progressive demands of their chosen industry.

Developmental validation of the DNAscan™ Rapid DNA Analysis™ instrument and expert system for reference sample processing

Since the implementation of forensic DNA typing in labs more than 20 years ago, the analysis procedures and data interpretation have always been conducted in a laboratory by highly trained and qualified scientific personnel. Rapid DNA technology has the potential to expand testing capabilities within forensic laboratories and to allow forensic STR analysis to be performed outside the physical boundaries of the traditional laboratory. The developmental validation of the DNAscan/ANDE Rapid DNA Analysis System was completed using a BioChipSet™ Cassette consumable designed for high DNA content samples, such as single source buccal swabs. A total of eight laboratories participated in the testing which totaled over 2300 swabs, and included nearly 1400 unique individuals. The goal of this extensive study was to obtain, document, analyze, and assess DNAscan and its internal Expert System to reliably genotype reference samples in a manner compliant with the FBI's Quality Assurance Standards (QAS) and the NDIS Operational Procedures. The DNAscan System provided high quality, concordant results for reference buccal swabs, including automated data analysis with an integrated Expert System. Seven external laboratories and NetBio, the developer of the technology, participated in the validation testing demonstrating the reproducibility and reliability of the system and its successful use in a variety of settings by numerous operators. The DNAscan System demonstrated limited cross reactivity with other species, was resilient in the presence of numerous inhibitors, and provided reproducible results for both buccal and purified DNA samples with sensitivity at a level appropriate for buccal swabs. The precision and resolution of the system met industry standards for detection of micro-variants and displayed single base resolution. PCR-based studies provided confidence that the system was robust and that the amplification reaction had been optimized to provide high quality results. The DNAscan integrated Expert System was examined as part of the Developmental Validation and successfully interpreted the over 2000 samples tested with over 99.998% concordant alleles. The system appropriately flagged samples for human review and failed both mixed samples and samples with insufficient genetic information. These results demonstrated the integrated Expert System makes correct allele calls without human intervention.