Developmental Validation of the PrepFiler™ Forensic DNA Extraction Kit for Extraction of Genomic DNA from Biological Samples*

Abstract

The PrepFiler Forensic DNA Extraction Kit enables isolation of genomic DNA from a variety of biological samples. The kit facilitates reversible binding of DNA with magnetic particles resulting in high DNA recovery from samples with very low and high quantities of biological materials: 0.1 and 40 microL of human blood (donor 2) provided 14 and 2883 ng of DNA, respectively. Following the revised SWGDAM guidelines, performance of the developed method was investigated using different sample types including saliva on swabs, semen stains on cotton fabric, samples exposed to environment, samples with polymerase chain reaction (PCR) inhibitors, blood stains (on denim, cotton cloth, and FTA paper), and touch evidence-type samples. DNA yields for all samples tested were equal or better than those obtained by both phenol-chloroform extraction and commercial kits tested. DNA obtained from these samples was free of detectable PCR inhibitors. Short tandem repeat profiles were complete, conclusive, and devoid of PCR artifacts.

A Sample Extraction Method for Faster, More Sensitive PCR-Based Detection of Pathogens in Blood Culture

“…HMW polysaccharide-based purification has proven to be particularly useful in forensics applications, where PCR inhibitors commonly encountered, 28 but this newer technology has not yet been tested on blood cultures that contain SPS. After several analytical experiments designed to examine the utility of these extraction methodologies in removing SPS and other inhibitors found in culture media, the three methodologies were compared for their ability to purify DNA from 60 blood cultures for accurate TaqMan analysis and to determine whether any of the methodologies offers an advantage in reducing TTR.…”

Automated Extraction of DNA from Forensic Sample Types Using the PrepFiler Automated Forensic DNA Extraction Kit

“…The stains of the body fluid on different substrates were prepared in our laboratory as described earlier. 10 The Freedom EVO 150 instrument and accompanying software and hardware are from Tecan Group Ltd. (Ma¨nnedorf, Switzerland).…”

“…18 We have 19 Validation studies to evaluate the performance of the PrepFiler Kit according to SWGDAM guidelines are described elsewhere. 10 This article describes the validation studies conducted to evaluate the performance of an automated DNA extraction method using the PrepFiler Automated Kit on the HID EVOlutioneExtraction System.…”

Assessing a novel room temperature DNA storage medium for forensic biological samples

“…We believe the data are sufficiently impressive to warrant further investigation by the forensic science community and consideration as a beneficial and effective means for extracted DNA storage. There are a greater range of samples that could be tested including those resulting from alternate extraction methods such as Chelex extracted DNA [23] or the new Prepfiler extraction method [24]. Storage studies utilizing DNA from additional extraction methods are underway; however, it is likely the outcome will be similar regardless of the condition of the sample, because truly dried samples are unlikely to degrade [10].…”