FORT LAUDERDALE, Fla. -- Edwin Southern, inventor of theSouthern blot, on Wednesday received the Special AchievementAward here at the Miami Winter Symposium. Harold Crews ofCoulter Corp., which sponsors the annual honor, presented theplaque.
The award, which was first presented in 1988, "recognizescontributions to biological science by way of new knowledge ormethodology whose impact was not particularly evident at thetime of the first description."
This was certainly the case with the now-ubiquitous labtechnique. In his acceptance address, Southern recalled thatwhen he developed the blot in 1973, he described the methodon a single mimeographed sheet, added a diagram, andcirculated it to colleagues in many laboratories. Since then, hetold BioWorld, "it's gone 'round the world."
Southern traces the origin of his technique, which transferssize-fractionated DNA restriction fragments from an agaroseelectrophoretic gel to a nitrocellulose (paper) membrane bycapillar blotting, to his school days. In 1949, he recalled, hehelped the headmistress of his school in the North of Englandduplicate exam papers on a gelatin-tray copier (the once-familiar precursor of the mimeograph machine).
"Water carried the violet-colored ink out of the gelatin --exactly the blotting process I later adapted to DNA," Southerntold BioWorld. "That's why it wouldn't be patentable."
Among Southern's favorite users of the blot is Alec Jefferies,who employed it in adapting restriction fragment lengthpolymorphism (RFLPs) to forensic, family and diseaseidentification. Circa 1988, a Ghanian youth sought to enterEngland to join his mother. The immigration service denied hisclaim of relatedness until Jefferies proved the mother-son DNAsimilarity.
Subsequently, other molecular biologists have literally boxedthe compass with Northern, Eastern and Western blottechniques. This nomenclature took hold after George Stock ofStanford University turned the Southern blot upside down bysubstituting messenger RNA for genomic DNA in the analysis."It became a lab joke," Southern said, "north being upside downfrom south."
Southern acknowledges that PCR (polymerase chain reaction)has largely superseded his blot and he is going with the flow.Among the family of new oligonucleotide techniques underdevelopment, Southern showed his audience a pulse-field/gelrotating model that alternates the electrical field, and a solid-state DNA synthesizer linked to glass-support matrices. Thepowerful techniques he and others are now developing, he said,"of course are the basis of PCR as well."
Southern's current research agenda includes mutationdetection, sequencing by hybridization and clinical applications.On this last point, the most exciting area is antisense oligos, hesaid. Because the targets are folded up, only small regions ofthem are actually accessible to oligo attack. His new techniques"can actually find which regions are amenable to attack," hesaid. "That's where I see the potential of this method as a firstapplication."
-- David N. Leff Science Editor
(c) 1997 American Health Consultants. All rights reserved.