Manual methods for PCR-based forensic DNA analysis.

This unit provides validated PCR-based methods to test for sequence polymorphisms and length polymorphisms. It includes a description of the reverse dot blot method for detecting sequence polymorphisms. The forensic PCR systems used to detect length polymorphisms are based on detection of different-sized PCR products following electrophoresis in either native or denaturing polyacrylamide gels. The unit offers a description of the amplification and detection of the variable number of tandem repeat (VNTR) length polymorphism at the D1S80 locus. It also describes the multiplex amplification of three separate autosomal short tandem repeats (STRs) and the X- and Y-linked amelogenin alleles. These PCR products are electrophoresed on a denaturing polyacrylamide gel. Support protocols for creating permanent records of silver-stained gels, checking the quality of reagents, and interpreting PCR-based tests are provided.