He continued as a graduate student (then Demonstrator, 1963) in the Department of Chemistry, University of Glasgow, where he was awarded his PhD in 1962.

The Southern blot is used for DNA analysis and was routinely used for genetic fingerprinting and paternity testing prior to the development of microsatellite markers for this purpose.

[13] The concepts of the Southern blot were used in the development and creation of the modern microarray slide, which is an extensively used experimental tool.

[17] He was made a Knight Bachelor in the June 2003 Birthday Honours for services to the development of DNA microarray technologies.

[21] His nomination for the Royal Society reads: Dr. Southern has done pioneering work on the organization of DNA sequences in chromosomes.

His 'blot' technique, for the identification of specific sequences among large populations of fragments generated by endonucleases, has found extremely widespread and important applications.