Cystic fibrosis serum effect on the short circuit current of rat jejunum

Sera from 100 subjects were tested for the presence of the cystic fibrosis (CF) "factor" utilizing the short circuit current rat jejunum bioassay. Comparing the mean percent decrease in short circuit current, the presumed normal group differs from the homozygous CF group at P = 0.001 and from the heterozygous group at P = 0.05. The two CF genotypes are statistically different at P = 0.004. There is, however, a large overlap among the three groups, which limits the assay's utility as a guide for factor purification as well as clinical use.