Validation of the AmpliFLP D1S80 PCR Amplification Kit for forensic casework analysis according to TWGDAM guidelines.

The validation of the AmpliFLP D1S80 PCR Amplification Kit for use in forensic casework was accomplished by performing all the relevant experiments outlined in the TWGDAM guidelines. Standard specimen and reproducibility studies were performed using organic and rapid DNA extraction techniques on both stain and liquid samples (blood, semen and saliva). Over 300 samples from three different populations (US Caucasians, African Americans and US Hispanics) were analyzed to determine allele and genotype frequencies. Purified DNA was mixed in defined ratios (ranging from unmixed DNA samples to 1:9 mixtures of 2 different DNA samples) prior to amplification to demonstrate that samples containing DNA from more than one individual can be detected and, in many cases, that the genotypes contributing to the mixture can be identified. Since casework samples frequently are exposed to environmental insults that can result in DNA degradation, purified DNA was degraded in the laboratory to analyze the effect of DNA fragment length on D1S80 amplification. It is crucial in the validation process to examine actual casework evidentiary material. This D1S80 kit can be used successfully by forensic scientists to amplify and type nonprobative evidentiary material, including bloodstains collected from crime scenes and rape kit materials collected for sexual assault cases. The D1S80 kit is specific to human DNA, and the D1S80 alleles are inherited according to the laws of Mendel. The sensitivity of the novel gel electrophoresis gel matrix allowed the PCR cycle number to be reduced to 29 cycles and the D1S80 kit sensitivity to be increased to 2.5 ng from the previous D1S80 Reagent Set specifications of 30 cycles and 5 ng, respectively.