During the last year we have improved both the hardware and the software of the system set up to analyze the two-dimensional electropherograms. We are also using this method to study protein synthesis in the yeast cell cycle: a) Hardware improvement. We have put in a microprocessor to control the film scanner. During a scan the microprocessor will accept data from the scanner, do some preliminary checking or averaging before writing them out to a magnetic tape. This set up eliminates tape errors and allows us to do different types of scanning and data averaging. The microprocessor is programmed to make the scanner scan one line, 1,2,4 or 8 times. It can also use a much smaller step on the scan then have data add up in an array of 1 by 1, 2 by 2, or 4 by 4 cells. b) Software improvement. Our computer programs can now automatically detect spots, split out overlapping spots and estimate the protein content of each spot. We have also written programs to automatically adjust for rotation, translation and local gel shrinkages in comparing spots coming from different gels. A multimatch program is written to correlate similar spots from a set of experiments (up to 10 gels) in order that they can be reached easily and analyzed. c) Experiments. During the past year, the heat shock response of S. Cerevisiae has been further analyzed. The patterns of protein synthesis by temperature-sensitive cell cycle mutants in a large number of cdc genes were examined. An analysis of protein synthesis in syachronous cell cycles using first-bud-cells ("virgin" cells) has been initiated.