Evaluation of the RapidHIT™ 200 System: A comparative study of its performance with Maxwell® DNA IQ™/Identifiler® Plus/ABI 3500xL workflow

RapidHIT™ System is a rapid DNA instrument that is capable of processing forensic samples from extraction through to capillary electrophoresis and profile generation within two hours. Evaluation of the RapidHIT™ 200 System was conducted to examine several key performance indicators of the instrument, including reproducibility, contamination, sensitivity, versatility and the possibility of sample re-extraction. Results indicated that the RapidHIT™ 200 System was capable of generating high quality DNA profiles which were comparable to those from the standard protocol comprising of Maxwell^® 16 DNA IQ™ System, Identifiler^® Plus and ABI 3500xL. No contamination was detected during the studies. Results also showed that the instrument was able to generate DNA profiles from samples containing lower amounts of DNA (0.5 μl of blood) albeit with more allele and locus dropouts when compared to the standard protocol. The ability to process blood swabs, blood-stained FTA punches, semen swabs, buccal swabs, product of conception (POC), bone marrow, fingernail clippings and cigarette butts at a good success rate indicated the robustness and versatility of the RapidHIT™ 200 System. Furthermore, additional alleles could be recovered via re-analysis of the failed samples using the standard protocol. In summary, our results showed that the RapidHIT™ 200 System was able to process casework samples for the purpose of providing rapid intelligence through DNA database searches and reference matching. Confirmative DNA results can be obtained through either concurrent processing of duplicate samples via standard protocol or re-extraction of samples retrieved from the RapidHIT™ sample cartridge.     

Internal validation of the RapidHIT® ID system

Traditionally, forensic DNA analysis has required highly skilled forensic geneticists in a dedicated laboratory to generate short tandem repeat (STR) profiles. STR profiles are routinely used either to associate or exclude potential donors of forensic biological evidence. The typing of forensic reference samples has become more demanding, especially with the requirement in some jurisdictions to DNA profile arrestees. The Rapid DNA (RDNA) platform, the RapidHIT^® ID (IntegenX^®, Pleasanton, CA), is a fully automated system capable of processing reference samples in approximately 90 min with minimal human intervention. Thus, the RapidHIT ID instrument can be deployed to non-laboratory environments (e.g., booking stations) and run by trained atypical personnel such as law enforcement. In order to implement the RapidHIT ID platform, validation studies are needed to define the performance and limitations of the system. Internal validation studies were undertaken with four early-production RapidHIT ID units. Reliable and concordant STR profiles were obtained from reference buccal swabs. Throughout the study, no contamination was observed. The overall first-pass success rate with an “expert-like system” was 72%, which is comparable to another current RDNA platform commercially available. The system’s second-pass success rate (involving manual interpretation on first-pass inconclusive results) increased to 90%. Inhibitors (i.e., coffee, smoking tobacco, and chewing tobacco) did not appear to affect typing by the instrument system; however, substrate (i.e., swab type) did impact typing success. Additionally, one desirable feature not available with other Rapid systems is that in the event of a system failed run, a swab can be recovered and subsequently re-analyzed in a new sample cartridge. Therefore, rarely should additional sampling or swab consumption be necessary. The RapidHIT ID system is a robust and reliable tool capable of generating complete STR profiles within the forensic DNA typing laboratory or with proper training in decentralized environments by non-laboratory personnel.     

An evaluation of the RapidHIT® system for reliably genotyping reference samples

Short tandem repeat (STR) typing is used routinely for associating or excluding individuals with biological evidence left at a crime scene. Improvements have been made to reduce the turnaround time and labor involved with profile generation, but there is still some lag time between sample collection and interpretation of results. The RapidHIT^® (IntegenX; Pleasanton, CA, USA) system is an automated instrument that is configured to perform DNA extraction, bead-based DNA normalization, amplification, electrophoresis of PCR amplicons, and data analysis of five reference swabs simultaneously. The RapidHIT system provided reliable STR profiles from reference buccal swabs in approximately 90 min with nominal “hands-on” sample loading time with no evidence of contamination between samples. The overall success rate of typing buccal swabs was comparable to standard typing systems. In the event of a failed run due to instrument failure, the swab can be removed from the cartridge and reanalyzed in the RapidHIT system or with standard STR genotyping workflows.     

Evaluation of the RapidHIT™ 200, an automated human identification system for STR analysis of single source samples

The RapidHIT™ 200 Human Identification System was evaluated to determine its suitability for STR analysis of single source buccal swabs. Overall, the RapidHIT™ 200 performed as well as our traditional capillary electrophoresis based method in producing useable profile information on a first-pass basis. General observations included 100% concordance with known profile information, consistent instrument performance after two weeks of buccal swab storage, and an absence of contamination in negative controls. When data analysis was performed by the instrument software, 95.3% of the 85 samples in the reproducibility study gave full profiles. Including the 81 full profiles, a total of 2682 alleles were correctly called by the instrument software, or 98.6% of 2720 possible alleles tested. Profile information was generated from as little as 10,000 nucleated cells, with swab collection technique being a major contributing factor to profile quality. The average peak-height-ratio for heterozygote profiles (81%) was comparable to conventional STR analysis, and while a high analytical threshold was required when offline profile analysis was performed (800 RFU), it was proportionally consistent with traditional methods. Stochastic sampling effects were evaluated, and a manageable approach to address limits of detection for homozygote profiles is provided. These results support consideration of the RapidHIT™ 200 as an acceptable alternative to conventional, laboratory based STR analysis for the testing of single source buccal samples, with review of profile information as a requirement until an expert software system is incorporated, and when proper developmental and internal validation studies have been completed.     

Developmental validation of the PowerPlex® ESI 16/17 Fast and PowerPlex® ESX 16/17 Fast Systems

The PowerPlex^® ESI 16 Fast, ESI 17 Fast, ESX 16 Fast, and ESX 17 Fast Systems represent faster cycling versions (50 min or less) of the PowerPlex^® ESI and ESX Systems released by Promega in 2009 to accommodate the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe. In addition to amplification of purified DNA samples, these new faster cycling systems allow for direct amplification from single-source blood and buccal samples deposited on FTA^® and nonFTA paper as well as from SwabSolution™ extracts of buccal swabs without the need for purification and quantitation. There are no changes to the autosomal primer pair sequences in the PowerPlex^® ESI Fast and ESX Fast Systems compared to the original multiplexes, and full concordance at all autosomal loci and amelogenin was observed with data generated previously with the original PowerPlex^® ESI and ESX Systems. This paper describes the developmental validation study performed on these new fast systems following guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM) and those of the DNA Advisory Board (DAB). Validation data demonstrate that these systems are sensitive for detecting low levels of DNA while also being capable of generating robust profiles from the high amount of input DNA present in direct-amplification samples. These systems are also tolerant to both high concentrations of PCR inhibitors as well as to slight variations in the final concentration of master mix and primer pair present in the amplification reaction that might be encountered due to pipetting error. The results of this validation study demonstrate that these systems may be used on multiple thermal cyclers and capillary electrophoresis platforms.     

Validation of a rapid DNA process with the RapidHIT® ID system using GlobalFiler® Express chemistry,a platform optimized for decentralized testing environments

The RapidHIT^® ID is a fully automated sample-to-answer system for short tandem repeat (STR)-based human identification. The RapidHIT ID has been optimized for use in decentralized environments and processes presumed single source DNA samples, generating Combined DNA Index System (CODIS)-compatible DNA profiles in less than 90 min. The system is easy to use, requiring less than one minute of hands-on time. Profiles are reviewed using centralized linking software, RapidLINK™ (IntegenX, Pleasanton, CA), a software tool designed to collate DNA profiles from single or multiple RapidHIT ID systems at different geographic locations. The RapidHIT ID has been designed to employ GlobalFiler^® Express and AmpFLSTR^® NGMSElect™, Thermo Fisher Scientific (Waltham, MA) STR chemistries. The Developmental Validation studies were performed using GlobalFiler^® Express with single source reference samples according to Scientific Working Group for DNA Analysis Methods guidelines. These results show that multiple RapidHIT ID systems networked with RapidLINK software form a highly reliable system for wide-scale deployment in locations such as police booking stations and border crossings enabling real-time testing of arrestees, potential human trafficking victims, and other instances where rapid turnaround is essential.     

A comparison of four methods for PCR inhibitor removal

Biological samples collected from the crime scenes often contain some compounds that can inhibit the polymerase chain reaction (PCR). The removal of PCR inhibitors from the extracts prior to the PCR amplification is vital for successful forensic DNA typing. This paper aimed to evaluate the ability of four different methods (PowerClean^® DNA Clean-Up kit, DNA IQ™ System, Phenol–Chloroform extraction and Chelex^®-100 methods) to remove eight commonly encountered PCR inhibitors including: melanin, humic acid, collagen, bile salt, hematin, calcium ions, indigo and urea. Each of these PCR inhibitors was effectively removed by the PowerClean^® DNA Clean-Up kit and DNA IQ™ System as demonstrated by generating more complete short tandem repeat (STR) profiles from the cleaned up inhibitor samples than from the raw inhibitor samples. The Phenol–Chloroform extraction and Chelex^®-100 methods, however, could only remove some of eight PCR inhibitors. Our results demonstrated that the PowerClean^® DNA Clean-Up kit and DNA IQ™ System were very effective for the removal of known PCR inhibitors that are routinely found in DNA extracts from forensic samples.     

Evaluation of the RapidHIT™ 200 and RapidHIT GlobalFiler® Express kit for fully automated STR genotyping

The RapidHIT™ 200 Human Identification System and RapidHIT GlobalFiler^® Express kit were evaluated and validated for use with single-source reference samples. It was of primary interest to evaluate the system for its efficacy as an expert system and to estimate a first pass success rate, as well as to identify the technical variables impacting that result. While results indicated that this instrument/kit combination can be used to accurately type single-source buccal samples, substantial variability in sensitivity and intra-color balance were observed, as were multiple artifacts, requiring extensive manual editing of the profiles. Artifacts included dye “blobs” and spectral overlap (pull-up) peaks that often originated from relatively low intensity allele peaks. Reduced intra-color balance, in combination with low sensitivity, occasionally resulted in instances of allelic dropout. Overall, 50% of the buccal samples analyzed in this study would have been successfully typed to give full GlobalFiler^® profiles without the need for manual review and editing.     

Improvement of short tandem repeat analysis of samples highly contaminated by humic acid

We investigated several methods for obtaining successful short tandem repeat (STR) results from high-humic acid (HA)-content samples. DNA purification efficiency was tested for QIAquick^® PCR Purification, QIAamp^® DNA Investigator and Prepfiler? Forensic DNA Extraction kits. HA-removal capacity of Inhibitor Remover and InhibitEX^® Tablet was tested. Experiments on overcoming HA effects on STR amplification were conducted using an AmpliTaq Gold^® DNA Polymerase and a TaKaRa Ex Taq? Hot Start Version (Ex Taq HS) with BSA addition. QIAquick kit was most efficient in HA removal and Ex Taq HS showed high resistance to HA. Increasing the amounts of Taq polymerases and BSA addition were shown to be efficient in overcoming PCR inhibition, but BSA addition was superior to the former method. Inhibitor Remover and InhibitEX^® Tablet did not positively affect the STR results. This study will help achieve better STR results with high-HA-content samples.     

Comparative evaluation of different extraction and quantification methods for forensic RNA analysis

Since about 2005, there is increasing interest in forensic RNA analysis whose versatility may very favorably complement traditional DNA profiling in forensic casework. There is, however, no method available specifically dedicated for extraction of RNA from forensically relevant sample material.In this study we compared five commercially available and commonly used RNA extraction kits and methods (mirVana™ miRNA Isolation Kit Ambion; Trizol^® Reagent, Invitrogen; NucleoSpin^® miRNA Kit Macherey-Nagel; AllPrep DNA/RNA Mini Kit and RNeasy^® Mini Kit both Qiagen) to assess their relative effectiveness of yielding RNA of good quality and their compatibility with co-extraction of DNA amenable to STR profiling.We set up samples of small amounts of dried blood, liquid saliva, semen and buccal mucosa that were aged for different time intervals for co-extraction of RNA and DNA. RNA quality was assessed by determination of ‘RNA integrity number’ (RIN) and quantitative PCR based expression analysis. DNA quality was assessed via monitoring STR typing success rates.By comparison, the different methods exhibited considerable differences between RNA and DNA yields, RNA quality values and expression levels, and STR profiling success, with the AllPrep DNA/RNA Mini Kit and the NucleoSpin^® miRNA Kit excelling at DNA co-extraction and RNA results, respectively.Overall, there was no ‘best’ method to satisfy all demands of comprehensible co-analysis of RNA and DNA and it appears that each method has specific merits and flaws. We recommend to cautiously choose from available methods and align its characteristics with the needs of the experimental setting at hand.     

Developmental validation of the Huaxia™ Platinum PCR amplification kit: A 6-dye multiplex direct amplification assay designed for Chinese reference samples

The Huaxia™ Platinum Kit for short tandem repeat (STR) amplification was designed to meet the needs of the rapidly growing Chinese forensic database. This PCR multiplex allows simultaneous amplification of the following autosomal loci: D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, Penta E, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, D6S1043, D10S1248, D1S1656, D12S391, D2S1338, Penta D and the gender-identification markers Yindel, and AMEL.The Huaxia™ Platinum Kit enables direct amplification from blood and buccal samples stored on treated and untreated paper, and features an optimized PCR protocol that yields time to results in less than 45 min. Developmental validation testing followed SWGDAM guidelines and demonstrated that this assay produces reproducible and accurate results. Studies on 798 individuals in 4 major Chinese ethnic groups produced highly concordant results with other commercially available STR genotyping kits. The validation results demonstrate that the Huaxia™ Platinum Kit is a robust and reliable identification system for forensic DNA databasing applications.     

Individual identification using the RapidHIT™ ID system for forensic samples

The RapidHIT™ ID system produces GlobalFiler™ analysis results after a short operating time. This device is effective because it automatically extracts DNA from oral mucosal cells or from blood stains and saliva collected at a crime scene, with subsequent polymerase chain reaction performed to produce a DNA profile. Two types of dedicated cartridges are available for RapidHIT™ ID: the RapidHIT™ ID ACE GlobalFiler Express sample cartridge for oral cells and other samples and the RapidINTEL™ sample cartridge for minute samples, such as blood stains. Previously validated specimens include oral mucosa cells and blood stains left at crime scenes. There have been no reports of blood and nail clipping samples collected from the postmortem bodies at the time of death. This report summarizes the results of using the RapidHIT™ ID system by collecting a variety of actual forensic samples from postmortem bodies at different stages of decomposition, which were subsequently analyzed using these cartridges.     

Internal validation of the GlobalFiler™ Express PCR Amplification Kit for the direct amplification of reference DNA samples on a high-throughput automated workflow

The GlobalFiler™ Express PCR Amplification Kit uses 6-dye fluorescent chemistry to enable multiplexing of 21 autosomal STRs, 1 Y-STR, 1 Y-indel and the sex-determining marker amelogenin. The kit is specifically designed for processing reference DNA samples in a high throughput manner. Validation studies were conducted to assess the performance and define the limitations of this direct amplification kit for typing blood and buccal reference DNA samples on various punchable collection media. Studies included thermal cycling sensitivity, reproducibility, precision, sensitivity of detection, minimum detection threshold, system contamination, stochastic threshold and concordance. Results showed that optimal amplification and injection parameters for a 1.2 mm punch from blood and buccal samples were 27 and 28 cycles, respectively, combined with a 12 s injection on an ABI 3500xL Genetic Analyzer. Minimum detection thresholds were set at 100 and 120 RFUs for 27 and 28 cycles, respectively, and it was suggested that data from positive amplification controls provided a better threshold representation. Stochastic thresholds were set at 250 and 400 RFUs for 27 and 28 cycles, respectively, as stochastic effects increased with cycle number. The minimum amount of input DNA resulting in a full profile was 0.5 ng, however, the optimum range determined was 2.5–10 ng. Profile quality from the GlobalFiler™ Express Kit and the previously validated AmpFlSTR® Identifiler® Direct Kit was comparable. The validation data support that reliable DNA typing results from reference DNA samples can be obtained using the GlobalFiler™ Express PCR Amplification Kit.     

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.     

Optimizing direct amplification of forensic commercial kits for STR determination

Direct DNA amplification in forensic genotyping reduces analytical time when large sample sets are being analyzed. The amplification success depends mainly upon two factors: on one hand, the PCR chemistry and, on the other, the type of solid substrate where the samples are deposited. We developed a workflow strategy aiming to optimize times and cost when starting from blood samples spotted onto diverse absorbent substrates. A set of 770 blood samples spotted onto Blood cards, Whatman^® 3 MM paper, FTA™ Classic cards, and Whatman^® Grade 1 was analyzed by a unified working strategy including a low-cost pre-treatment, a PCR amplification volume scale-down, and the use of the 3500 Genetic Analyzer as the analytical platform. Samples were analyzed using three different commercial multiplex STR direct amplification kits. The efficiency of the strategy was evidenced by a higher percentage of high-quality profiles obtained (over 94%), a reduced number of re-injections (average 3.2%), and a reduced amplification failure rate (lower than 5%). Average peak height ratio among different commercial kits was 0.91, and the intra-locus balance showed values ranging from 0.92 to 0.94. A comparison with previously reported results was performed demonstrating the efficiency of the proposed modifications. The protocol described herein showed high performance, producing optimal quality profiles, and being both time and cost effective.     

Null alleles and sequence variations at primer binding sites of STR loci within multiplex typing systems

Rare variants are widely observed in human genome and sequence variations at primer binding sites might impair the process of PCR amplification resulting in dropouts of alleles, named as null alleles. In this study, 5 cases from routine paternity testing using PowerPlex^®21 System for STR genotyping were considered to harbor null alleles at TH01, FGA, D5S818, D8S1179, and D16S539, respectively. The dropout of alleles was confirmed by using alternative commercial kits AGCU Expressmarker 22 PCR amplification kit and AmpFℓSTR^®. Identifiler^® Plus Kit, and sequencing results revealed a single base variation at the primer binding site of each STR locus. Results from the collection of previous reports show that null alleles at D5S818 were frequently observed in population detected by two PowerPlex^® typing systems and null alleles at D19S433 were mostly observed in Japanese population detected by two AmpFℓSTR™ typing systems. Furthermore, the most popular mutation type appeared the transition from C to T with G to A, which might have a potential relationship with DNA methylation. Altogether, these results can provide helpful information in forensic practice to the elimination of genotyping discrepancy and the development of primer sets.     

Developmental validation of the AmpFℓSTR® NGM SElect™ PCR Amplification Kit: A next-generation STR multiplex with the SE33 locus

The AmpFℓSTR^® NGM SElect™ PCR Amplification Kit is a new 17-plex STR genotyping kit designed for use primarily in forensic casework analysis. The kit was designed to be a counterpart to the AmpFℓSTR^® NGM™ Kit for laboratories wishing to add the SE33 locus to the new European Standard Set of STR loci. The NGM SElect Kit shares the same primer sets for 16 common loci with the NGM Kit (D10S1248, D3S1358, vWA, D16S539, D2S1338, amelogenin, D8S1179, D21S11, D18S51, D19S433, TH01, FGA, D22S1045, D2S441, D1S1656 and D12S391), with additional primers for the SE33 locus. Developmental validation studies followed the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines for STR kit manufacturers and tested several critical areas of kit performance including a sensitivity series, DNA mixtures and inhibited samples. The studies demonstrated that the NGM SElect Kit provides equivalent overall performance to the NGM Kit, but with even greater discriminatory power due to the inclusion of the highly informative SE33 locus.     

Stochastic sampling effects in STR typing: Implications for analysis and interpretation

The analysis and interpretation of forensic STR typing results can become more complicated when reduced template amounts are used for PCR amplification due to increased stochastic effects. These effects are typically observed as reduced heterozygous peak-height balance and increased frequency of undetected alleles (allelic “dropout”). To investigate the origins of these effects, a study was performed using the AmpFlSTR^® Identifiler Plus^® and MiniFiler^® kits to amplify replicates from a dilution series of NIST Human DNA Quantitation Standard (SRM^® 2372A). The resulting amplicons were resolved and detected on two different genetic analyzer platforms, the Applied Biosystems 3130xL and 3500 analyzers. Results from our study show that the four different STR/genetic analyzer combinations exhibited very similar peak-height ratio statistics when normalized for the amount of template DNA in the PCR. Peak-height ratio statistics were successfully modeled using the Poisson distribution to simulate pre-PCR stochastic sampling of the alleles, confirming earlier explanations that sampling is the primary source for peak-height imbalance in reduced template dilutions. In addition, template-based pre-PCR sampling simulations also successfully predicted allelic dropout frequencies, as modeled by logistic regression methods, for the low-template DNA dilutions. We discuss the possibility that an accurately quantified DNA template might be used to characterize the linear signal response for data collected using different STR kits or genetic analyzer platforms, so as to provide a standardized approach for comparing results obtained from different STR/CE combinations and to aid in validation studies.     

Performance of Identifiler Direct and PowerPlex 16 HS on the Applied Biosystems 3730 DNA Analyzer for processing biological samples archived on FTA cards

Direct amplification of STR loci from biological samples collected on FTA cards without prior DNA purification was evaluated using Identifiler Direct and PowerPlex 16 HS in conjunction with the use of a high throughput Applied Biosystems 3730 DNA Analyzer. In order to reduce the overall sample processing cost, reduced PCR volumes combined with various FTA disk sizes were tested. Optimized STR profiles were obtained using a 0.53 mm disk size in 10 μL PCR volume for both STR systems. These protocols proved effective in generating high quality profiles on the 3730 DNA Analyzer from both blood and buccal FTA samples. Reproducibility, concordance, robustness, sample stability and profile quality were assessed using a collection of blood and buccal samples on FTA cards from volunteer donors as well as from convicted offenders. The new developed protocols offer enhanced throughput capability and cost effectiveness without compromising the robustness and quality of the STR profiles obtained. These results support the use of these protocols for processing convicted offender samples submitted to the National DNA Data Bank of Canada. Similar protocols could be applied to the processing of casework reference samples or in paternity or family relationship testing.     

Optimization of DNA extraction and sampling methods for successful forensic microbiome analyses of the skin and saliva

Microbiome studies have contributed to many fields, such as healthcare and medicine; however, these studies are relatively limited in forensics. Microbiome analyses can provide information, such as geolocation and ancestry information, when short tandem repeat (STR) profiling fails. In this study, methods for DNA extraction and sampling from the skin and saliva were optimized for the construction of a Korean Forensic Microbiome Database (KFMD). DNA yields were estimated using four DNA extraction kits, including two automated kits (Maxwell® FSC DNA IQ™ Casework Kit and PrepFiler™ Forensic DNA Extraction Kit, updated) and two manual kits (QIAamp DNA Mini Kit and QIAamp DNA Micro Kit) commonly used in forensic DNA profiling laboratories. Next-generation sequencing of the 16S rRNA V4 region was performed to analyze microbial communities in samples. The Bacterial Transport Swab with Liquid Media (NobleBio), two cotton swabs (PoongSung and Puritan), and nylon-flocked swabs (NobleBio and COPAN) were tested for DNA recovery. The PrepFiler and Maxwell kits showed the highest yields of 3.884 ng/μL and 23.767 ng/μL from the scalp and saliva, respectively. With respect to DNA recovery, nylon-flocked swabs performed better than cotton swabs. The relative abundances of taxa sorted by DNA extraction kits were similar contributions; however, with significant differences in community composition between scalp and saliva samples. Lawsonella and Veillonella were the most abundant genera in the two sample types. Thus, the Maxwell® FSC DNA IQ™ Casework Kit and nylon-flocked swab (NobleBio) were optimal for DNA extraction and collection in microbiome analyses.