The Southern Blot: An Update

The Southern blot technique, published by Southern in 1975 (1 ), is probably the most widely used method in molecular biology and, to date, has received in excess of 100,000 literature citations. The purpose of the method is the detection of gel-fractionated DNA molecules following transfer to a membrane. The Southern blot is used extensively in research applications (e.g., gene mapping) as well as in diagnosis (e.g., DNA fingerprinting, Chapter 22 ; inherited disorders, Chapter 30 ).