Following the discovery of the structure of DNA in 1953, it became dear that scientists needed to be able to distinguish different DNA sequences. In 1975, Edward Southern published details of a new method for detecting DNA fragments based upon their specific sequence. An indication of the importance of his work is that the technique was eponymously named after him and that subsequent methods based loosely on similar principles were named using 3 play on his surname (western and northern blot). The simplicity and effectiveness of the technique led to its universal acceptance as a standard method for identification of DNA sequences. In the modern laboratory where turn-around times assume ever greater importance, the process can seem relatively time-consuming. In some cases, this has led to its replacement by more rapid techniques such as long-range PCR. Nevertheless, more than 30 years after its invention, the Southern blot remains a cornerstone of molecular biology.