Electrophoretic patterns of proteins in cystic fibrosis sweat

The abnormal gene product in cystic fibrosis has not been identified. We report that two-dimensional polyacrylamide gel electrophoresis of 125I-labeled sweat proteins coupled with fluorography and rare earth screen radioautography reveals an absence of an acidic protein of molecular weight 60,000 in sweat collected from 9 patients with cystic fibrosis. The protein spot was present in sweat from heterozygotes and from controls.