can anyone please tell me the exact nature of the his3(delta)1 deletion in yeast strain S150. How much of the gene is missing, and which bit? Andrew Mayes Alan Colley, Tel: (0131) 650 7097 ICMB, e-mail: ACOLLEY at srv0.bio.ed.ac.uk University of Edinburgh, Swann Building, Kings Buildings, Edinburgh, United Kingdom, EH9 3JR.