Recovery and Stability of DNA in Samples of Forensic Science Significance

The ability to recover sufficient amounts of deoxyribonucleic acid (DNA) from various biological evidentiary samples for individualization purposes is discussed. The chemistry and stability of DNA under various conditions is reviewed. The recovery of nondegraded DNA bears directly on the ability to successfully analyze such samples by restriction fragment length polymorphism analysis, as well as by methods utilizing the polymerase chain reaction (PCR), which includes (1) reverse dot-blot hybridization using allele-specific oligonucleotide probes and (2) allele-specific fragment length polymorphism analysis, steroids with A-ring modifications, steroids with an extra ring, and steroids with B-ring and C-ring modifications. Common metabolic pathways are noted and summarized.