Coult N, Cronk SM, Haverstick DM, Kinnon P, Landers JP, Lounsbury JA, Miranian DC, Saul DJ (2012) An enzyme-based DNA preparation method for application to forensicbiological samples and degraded stains. Forensic Science International Genetics 6(5): 607-615).

Extraction of DNA from forensic samples typically uses either an organic extraction protocol or solid phase extraction (SPE) and these methods generally involve numerous sample transfer, wash and centrifugation steps. Although SPE has been successfully adapted to the microdevice, it can be problematic because of lengthy load times and uneven packing of the solid phase. A closed-tube enzyme-based DNA preparation method has  been developed which uses a neutral proteinase to lyse cells and degrade proteins and nucleases [14]. Following a 20 min incubation of the buccal or whole blood sample with this proteinase, DNA is polymerase chain reaction (PCR)-ready.

This paper describes the optimization and quantitation of DNA yield using this method, and application to forensic biological samples, including UV- and heat-degraded whole blood samples on cotton or blue denim substrates. Results demonstrate that DNA yield can be increased from 1.42 (±0.21) ng/μL to 7.78 (±1.40) ng/μL by increasing the quantity of enzyme per reaction by 3-fold. Additionally, there is a linear relationship between the amount of starting cellular material added and the concentration of DNA in the solution, thereby allowing DNA yield estimations to be made. In addition, short tandem repeat (STR) profile results obtained using DNA prepared with the enzyme method were comparable to those obtained with a conventional SPE method, resulting in full STR profiles (16 of 16 loci) from liquid samples (buccal swab eluate and whole blood), dried buccal swabs and bloodstains and partial profiles from UV or heat-degraded bloodstains on cotton or blue denim substrates. Finally, the DNA preparation method is shown to be adaptable to glass or poly(methyl methacrylate) (PMMA) microdevices with little impact on STR peak height but providing a 20-fold reduction in incubation time (as little as 60 s), leading to a ≥1 h reduction in DNA preparation time.

Download Now will open in new tab

Related Products

forensicGEM Universal

MicroGEM's forensicGEM Universal Kit provides users with a single tube solution for extracting DNA from a variety of forensically-relevant human samples.

Extracts DNA from forensic samples including saliva (liquid, swab, stains, storage card – FTA), blood (liquid, swab, stains, storage card – FTA), and tissue (solid, hair).

Produces high-quality single-stranded DNA proven for use with STR, PCR, qPCR and whole genome amplification.

Each kit contains forensicGEM, Histosolv, BLUE buffer, RED+ buffer and ORANGE+ buffer.

View Product