Somatic mutation studies in human lymphoid cells: The detectability of quantitative genetic variants in two‐dimensional gels

The feasibility of detecting quantitative genetic variants based on a decrease in the integrated intensity of polypeptide spots in two‐dimensional polyacrylamide gels of human lymphoblastoid cell clones was investigated. A battery of 65 spots on 115 gels was studied to determine the distribution of quantitative measures for spots where no mutation had occurred. The corresponding distribution for spots which have decreased integrated intensity as a result of a mutation at one of two alleles coding for the spot was investigated by quantitating spots for which mutations were known to have occurred. These two distributions allowed the estimation of the rates of false positive and false negative errors for any particular strategy aimed at detecting null mutations, and thus provides a basis for the design of efficient strategies. Our silver stained gels have sufficient reproducibility of spot integrated intensities so that, for situations in which the mutation rate is relatively high, it is practical to monitor a sub‐set of spots for null variants using the same digitized images as are used to detect structural variants.