Human Genetics

Recombination and Mutation

DNA fingerprinting has gone through an evolution of ever better techniques over the past thirty years. The initially prevalent technique for fingerprinting was RFLP analysis (restriction fragment length polymorphism). In this technique, human DNA cleaved by restriction enzymes yields an individual pattern upon electrophoresis. RFLP methods have been replaced by other techniques, all of which have been greatly assisted by the advent of PCR, polymerase chain reaction, which enables DNA replication in vitro. These other methods of DNA fingerprinting include discriminating individuals based on SNPs (single nucleotide polymorphisms). Another technique is called AmpFLP (amplified fragment length polymorphism), which relies on PCR to amplify the sample which is electrophoresed and analyzed based on variable number tandem repeat (VNTR) polymorphisms. Lastly, the preferred technique for DNA fingerprinting these days is STR analysis, based on PCR and analysis of differences in short tandem repeats (STR). STRs are highly polymorphic regions that have short repeated sequences of DNA the number of which is variable among individuals.

This material is itself not difficult. It just takes enough reading around to become familiar with all the acronyms.