ABSTRACT
The turn-around time of urgent crime scene DNA samples is often far longer than desired by law enforcement. Crime scene DNA sample processing involves both complex and routine processing steps. Simplification and integration of the routine steps would dramatically improve turn-around time and reduce the risk of operator contamination. Routine DNA extraction and quantitation is readily available. However, PCR amplification and electrophoretic analysis remain largely manual. Rapid DNA Analysis is a hands-free "swab in - profile out" process which consists of automated DNA extraction, amplification, separation, detection, and allele calling without human intervention. RapidHIT® 200 and RapidHIT ID are rapid DNA systems developed by IntegenX (Pleasanton, CA) and validated for the use of buccal swabs. A new generation of the RapidHIT sample cartridge for RapidHIT ID has been designed and tested which allows the loading of extracted and quantified DNA. RapidHIT EXT sample cartridge allows a user to generate a forensic DNA profile from less than 250â¯pg of extracted and quantified DNA in less than 90â¯min with less than one-minute hands-on time. Once the sample is loaded in the RapidHIT EXT sample cartridge, a DNA profile is produced after amplification, detection and automated data analysis. We report on sensitivity, reproducibility, concordance, DNA mixtures and carryover for EXT sample cartridges pre-loaded with GlobalFiler® Express and AmpFLSTR® NGM SElect™ Express, (Thermo Fisher Scientific, Waltham, MA) STR chemistries. Purified and quantified DNA from mock crime scene samples were used to demonstrate the utility of these cartridges in an established forensic laboratory.
Subject(s)
DNA Fingerprinting/instrumentation , Microsatellite Repeats , DNA/analysis , DNA Fingerprinting/methods , Electrophoresis, Capillary , Female , Humans , Male , Polymerase Chain Reaction , Reproducibility of Results , Time FactorsABSTRACT
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 90min. 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.
Subject(s)
DNA Fingerprinting , DNA/genetics , High-Throughput Nucleotide Sequencing/instrumentation , Microsatellite Repeats , Animals , Humans , Reproducibility of Results , Software , Species SpecificityABSTRACT
UNLABELLED: Short tandem repeat (STR) DNA typing is a global standard for human identification. Current practice involves highly trained forensic analysts, operating in a laboratory setting, using multiple instruments to process samples and analyze the data. Here, we report the developmental validation of a fully integrated and automated DNA profiling system, the RapidHIT® System, capable of producing up to five high quality STR profiles with full controls in approximately 90min using PowerPlex®16 HS RapidHIT chemistry. The system integrates all sample handling steps: starting from lysis of cells on buccal swabs or other buccal sample types through DNA extraction, normalization, amplification,capillary array electrophoresis, detection, and integrated software analysis. The results describe the developmental validation of the RapidHIT™ System for buccal samples processed with the DNA IQ™ extraction chemistry using a guandinium chaotropic agent and paramagnetic beads followed by amplification using a modified version of PowerPlex 16 HS chemistry (PowerPlex 16 HS RapidHIT chemistry), and capillary electrophoresis with manual review of genotyping data following interpretation guidelines. All processing from the buccal swab to generation and processing of the profile occurs on the RapidHIT platform. RESULT: are concordant with traditional methods, with 88% first pass success rates for both the CODIS and PowerPlex 16 loci. Average peak height ratios were 0.89 for buccal swabs. The system produces full profiles from swabs with at least 176 ng of saliva DNA. Rapid DNA identification systems will significantly enhance capabilities for forensic labs, intelligence, defense, law enforcement, refugee and immigration applications, and kinship analysis.
Subject(s)
Forensic Anthropology , Mouth Mucosa/metabolism , Humans , Microsatellite Repeats/genetics , Polymerase Chain Reaction , Reproducibility of ResultsABSTRACT
A polymer microchip with an open tip for electrospray mass spectrometry is presented. The tip consists of a groove with parallel walls where a droplet can form at the end surface. A lid covers the whole chip except at the microchannel tip, which is left open. Poly(dimethylsiloxane) (PDMS) microchips were cast using a nickel mould which in turn was replicated from a dry etched silicon wafer. Tips with microchannel widths of around 50 microm could easily be replicated. Since the tip had no cover, the assembly of microchip and cover was simplified. A total ion current variation of 5% during 300 s was achieved for a 1 microM myoglobin solution. The non-complex design of the cover makes it suitable for versatile tests of chip prototypes. The nickel mould was found to be useful for PDMS microstructure fabrication. Also, such a robust mould allows casting electrospray tips in more rigid thermoset materials.