Introduced by John Maddox
A small virus, phiX174, is the extraordinary organism at the centre of one of the most important advances in genetic research. It is in this virus that, for the first time, the complete molecular structure-of the genes has been mapped. With this knowledge the interpretation of living processes will be possible in purely molecular terms. Dr Fred Sanger, from the MR6 Laboratory of Molecular Biology in Cambridge, reflects on the implications of this work. In the same laboratory Dr Cesar Milstein investigates mutation rates at a molecular level which he believes will give insights into the body's immune responses and possibly ageing and carcinogenesis. Editor Thelma Rumsey