Biological Basis for DNA Evidence
This chapter provides a brief background to the biotechnology relevant to the interpretation of short tandem repeat (STR) samples. With the recent advances in deoxyribonucleic acid (DNA) sequencing methodology and bioinformatics, next-generation sequencing technologies are becoming more available. The DNA of humans and many other organisms has been used in forensic work. The areas of the human genome used for DNA STR profiling are largely intronic. Some harmonization of STR loci used in forensic work has been achieved by collaboration at the international level. The chapter presents the process of interpreting electropherograms. The greatest advantage of fluorescence-automated sequencer technology is the ability to detect several different dye-labelled moieties. Linking the allelic ladder and the nomenclature of STR loci provides the key to standardization. The allelic ladders act as control reference standards that enable laboratories using different hardware and multiplexes to compare results.