Signature Science supports our clients by providing cost-effective, scalable casework solutions for both traditional and specialized sample analysis. Because we, too, want to solve every case, the experts of our Center for Advanced Genomics® engage in high-level genomic research, development, and testing and evaluation to address the scientific and technical forensic challenges facing our criminal justice system.
Forensic DNA Casework
State and local law enforcement crime laboratories across the U.S. rely on Signature Science’s ANAB-accredited DNA casework laboratory to provide high-quality analysis and training services on time, every time.
Our ANAB-Accredited Laboratory and Skilled Analysts offer:
- Extraction and quantification of DNA
- Investigator 24Plex
- Yfiler® Plus
- Probabilistic genotyping with STRmix™
- Body fluid identification & evidence screening
- Male screening and stop-at-quant testing
- Expert witness testimony & consultations
- Case & data review
- Validated solutions for challenging sample types
- FRISC® (Shell Casing extraction and analysis)
- Forensic Genetic Genealogy
- Global Screening Array using iScan™
- Bone, hair, blood, semen, teeth, buccal swabs
Forensic Genetic Genealogy (FGG)
In cases of degraded DNA and challenging sample types, Signature Science’s CAG combines its validated in-house SNP genotyping method with genetic genealogy services from experienced researchers to offer a Forensic Genetic Genealogy service that can provide investigative leads from DNA inputs 1000x lower than industry standards.
CAG Scientists Validate GSA for Forensic Lab Use
CAG scientists validated of the Illumina® Infinium Assay using the GSA on the iScan™ System for use in Forensic Laboratories. This validation characterized the performance of forensic samples on the GSA platform, providing valuable insight into what forensic practitioners can expect from microarray-based genotyping data.
FGG Services FAQ
What is the FGG Case Review Process?
The CAG team, made up of forensic scientists, bioinformaticians, and genealogists, works closely with law enforcement clients to determine if their case samples are suitable for genotyping and compliant with the current U.S. Department of Justice policy on FGG DNA analysis and searching. Criteria include, but are not limited to:
- Case involves an unsolved violent crime, and the candidate forensic sample is from a putative perpetrator, or unidentified remains of a suspected homicide victim (‘unidentified human remains’).
- The forensic profile derived from the candidate forensic sample must have been uploaded to CODIS, and subsequent CODIS searches must have failed to produce a probative and confirmed DNA match.
How are samples quantified and processed?
Candidate sample extracts submitted for FGG are first quantified using the Investigator Quantiplex Pro Kit to ensure sufficient quantity (minimum concentration of 0.05 ng/μL, in a minimum volume of 10 μL) and quality are present for SNP genotyping. Candidate samples approved for FGG analysis are prepared in-house for SNP genotyping using the Infinium Global Screening Array-24 Kit and run on the Illumina iScan. The microarray contains over 650,000 SNP markers.
Will FGG work for low-input or degraded samples?
The CAG’s developmental validation has demonstrated successful genotyping with DNA input levels down to 0.2 ng gDNA, three orders of magnitude lower than the manufacturer’s recommended input of 200 ng gDNA. Successful genotyping, eligible for GEDMatch® Pro upload, has also been shown from degraded samples (e.g., bone) with various insults including cremation, embalming and surface decomp.
How will data be analyzed and uploaded to reference databases?
Microarray data are visualized and analyzed using Illumina’s GenomeStudio Software. The data generated undergo rigorous quality assessment, followed by upload into GEDmatch® for finding genetic relatives. Formatted data are uploaded into FamilyTreeDNA (FTDNA) on a case-by-case basis. Additionally, upon request, data can be analyzed to provide phenotypic information such as biogeographic ancestry and hair, eye and skin color.
How are investigative leads generated?
Genetic genealogy research is performed on the DNA data output file with the goal of generating leads for our law enforcement clients. Through this process, leads such as ethnicity composition, surnames, familial geographic locations, and DNA relatives may be noted. Each individual piece of information collected is considered a lead and is reported to our law enforcement client.
Are there other FGG options for degraded and low-input DNA samples?
The CAG team is finalizing for publication our internal validation of the Verogen ForenSeq® Kintelligence workflow for the NDIS-approved MiSeq FGx® Sequencing System. ForenSeq Kintelligence, an FGG solution based on next-generation sequencing technology, targets forensically relevant markers along with ancestry, identity, and phenotype markers to estimate kinship. The workflow is optimized for degraded and low-input DNA samples from a range of sample types including blood, bone, buccal swabs, hair, teeth, semen, and touch DNA (e.g., tape and spent shell casings). Additionally, successful genotyping with sufficient results for GEDMatch® Pro have resulted with various insults to include cremains and burned and surface decomposed bone.
Leslie Parke, PMP, CQA
Director, Forensic DNA Laboratory
For more information about Forensic DNA Casework
Christina Neal, MS, PMP
For more information about Forensic Genetic Genealogy
Training and Validation Services
Our mission is to help solve every case, and we can help arm DNA analysts and case investigators with the knowledge to get it done. Our topical, practical training courses and validation services are tailored to the needs of individual laboratories, departments, and agencies and can be held at our Austin and Charlottesville locations, or onsite at your agency.
Selected Training Topics:
- General and STRmix™ Expert Witness Testimony
- DNA on Items of Evidence (What to Collect, Best Items to Send in for Testing)
- Techniques for Collecting and Handling Evidence to Facilitate DNA Testing (e.g., Shell Casings)
- Understanding Serology and DNA Reports
- Enhanced Workflows
- Forenseq™ Kintelligence
- Whole Genome Sequencing
- Targeted Sequencing
- Array Genotyping
Selected Validation Services:
- Enhanced Laboratory Workflow Set Up
- Workflow Validation Support
- Validation Planning
- Validation Execution
- Data Analysis
- Validation Report Writing
- SOP Development
For more information about Training and Validation Services:
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