Assessment of autosomal and male DNA extracted from casework samples using Casework Direct Kit, Custom and Maxwell 16 System DNA IQ Casework Pro Kit for autosomal-STR and Y-STR profiling

Abstract

Short repetitive regions in autosomal and Y chromosomes known as short tandem repeats (STRs) are currently used for DNA profiling in crime investigations. However, DNA profiling requires a sufficient quality and quantity of DNA template, which is often not obtained from trace evidence or degraded biological samples collected at the scene of a crime. Here, we assessed autosomal and male DNA components extracted from crime scene and mock casework samples using the Casework Direct Kit, Custom and compared the results against those obtained by extraction of matching samples using well-established Maxwell 16 System DNA IQ Casework Pro Kit. The quantity and quality of extracted DNA obtained using both Casework Direct Kit, Custom and Maxwell 16 System DNA IQ Casework Pro Kit were analyzed using PowerQuant Systems followed by autosomal and Y-chromosome STR profiling using GlobalFiler Express PCR Amplification Kit and PowerPlex Y23 System, respectively. Our results showed that the Casework Direct Kit and Maxwell 16 DNA IQ Casework Pro Kit have more or less equal capacity to extract inhibitor free DNA, but that the latter produces slightly better quality and more DNA template and subsequently higher numbers of STR allele calls for autosomal and Y-STR analyses. Nonetheless, the Casework Direct Kit, Custom is the quicker and cheaper option for extraction of good, clean DNA from high content material and might best be used for extraction of reference samples. Such reference DNA samples typically come from buccal swabs or freshly drawn blood. So, in general, they can confidently be expected to have a high nucleic acid content and to be inhibitor-free.

Recent trends and developments in forensic DNA extraction

“…Reagents that directly lyse cells in casework (i.e., non‐reference) samples have also been developed. For example, the Casework Direct kit, Custom (Promega) contains a buffer and reducing agent to generate PCR amplification‐ready lysates from biological stains and touch samples (Graham et al, 2018; Hakim et al, 2019). In one study, the authors used a combination of microFLOQ™ Direct swabs for sample collection together with pre‐PCR amplification treatment using the Casework Direct kit, Custom to prepare lysates for direct PCR amplification (Sherier et al, 2020).…”

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

“…Recent studies testing these direct casework kits have demonstrated the successful genotyping of a wide variety of sample types, with comparable or improved results over traditional processing methods [44,45,59,77–79]. One such study performed by Sherier et al focused on the optimization of a modified direct PCR method using the Casework Direct Kit, Custom (Promega) for various dilutions of body fluid stains (blood, semen, saliva; neat‐1:100 dilution) on cloth [44].…”

Towards Next-Generation Sequencing (NGS)-Based Newborn Screening: A Technical Study to Prepare for the Challenges Ahead

“…We will use a previously developed automated method that was tested in our laboratory. To use as little material as possible, DNA will be extracted from one blood spot (approximately 50 µL) [ 17 ], after which DNA will be isolated on a solid support from the Protocol IQ Casework Pro Kit for Maxwell 16 (Promega, Madison, WI, USA) (IQ) [ 35 ]. If needed, we will also test other DNA extraction methods.…”