Investigative Genetics · 2016 · 41 citations · 31 references
MedicineBiologyGeneticsForensic PathologyGenomicsMolecular DiagnosticsNucleic Acid ExtractionSpecimen HandlingSpecimen ProcessingClinical Sample ProcessingDna ExtractionDna Extraction From Degraded SamplesForensic Dna AnalysisForensic Dna IdentificationForensic Sample PreparationForensicsPostmortem Victim Identification
Low DNA content (LDC) samples, such as epithelial transfers, blood spatter, and small tissue fragments, are critical in disaster response, military, forensic, and medical examiner contexts, yet their processing demands experienced staff, specialized equipment, and complex procedures. The study introduces a rapid DNA analysis system that enables non‑technical operators to generate STR profiles from LDC samples in field‑forward settings. The system uses a Low DNA Content BioChipSet integrated into the Accelerated Nuclear DNA Equipment, performing efficient DNA purification and microfluidic ultrafiltration to maximize DNA for amplification and electrophoretic detection. The system achieves casework‑level accuracy, precision, and resolution, enabling rapid generation of STR profiles from diverse sample types and reducing turnaround time, while an integrated Expert System interprets results without a technical operator. Reference: 4(1):1-15, 2013.
Short tandem repeat (STR) analysis of casework samples with low DNA content include those resulting from the transfer of epithelial cells from the skin to an object (e.g., cells on a water bottle, or brim of a cap), blood spatter stains, and small bone and tissue fragments. Low DNA content (LDC) samples are important in a wide range of settings, including disaster response teams to assist in victim identification and family reunification, military operations to identify friend or foe, criminal forensics to identify suspects and exonerate the innocent, and medical examiner and coroner offices to identify missing persons. Processing LDC samples requires experienced laboratory personnel, isolated workstations, and sophisticated equipment, requires transport time, and involves complex procedures. We present a rapid DNA analysis system designed specifically to generate STR profiles from LDC samples in field-forward settings by non-technical operators. By performing STR in the field, close to the site of collection, rapid DNA analysis has the potential to increase throughput and to provide actionable information in real time.A Low DNA Content BioChipSet (LDC BCS) was developed and manufactured by injection molding. It was designed to function in the fully integrated Accelerated Nuclear DNA Equipment (ANDE) instrument previously designed for analysis of buccal swab and other high DNA content samples (Investigative Genet. 4(1):1-15, 2013). The LDC BCS performs efficient DNA purification followed by microfluidic ultrafiltration of the purified DNA, maximizing the quantity of DNA available for subsequent amplification and electrophoretic separation and detection of amplified fragments. The system demonstrates accuracy, precision, resolution, signal strength, and peak height ratios appropriate for casework analysis.The LDC rapid DNA analysis system is effective for the generation of STR profiles from a wide range of sample types. The technology broadens the range of sample types that can be processed and minimizes the time between sample collection, sample processing and analysis, and generation of actionable intelligence. The fully integrated Expert System is capable of interpreting a wide range or sample types and input DNA quantities, allowing samples to be processed and interpreted without a technical operator.
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