Genetic analysis using the polymerase chain reaction.

The ability of PCR to amplify a specific DNA segment from a complex template in an automated reaction has made molecular analysis more accessible both to basic research and diagnostic laboratories. Modifications of the basic PCR method using generic primers now allow DNA amplification even in the absence of specific nucleotide sequence information. Although PCR has proved extremely valuable for detecting the presence or absence of a given sequence (e.g. diagnosis of infectious disease pathogens like HIV), it is uniquely suited to analyze genetic variation in the amplified DNA. The capacity to analyze DNA variation from limited samples like hair or cheek scrapings has made genetic diagnosis and population genetics studies much simpler and the amplification of specific sequences from individual cells (e.g. sperm) has opened new approaches to genetic mapping.