Abstract
An antiserum raised in guineapigs showed positive immunoelectrophoretic reaction with sera from 16 of 17 patients with cystic fibrosis, 8 of 9 obligate heterozygotes, and only 1 of 15 normal subjects. The antiserum appeared to be specific to the cystic-fibrosis protein described by Wilson and colleagues. Precipitin peaks were larger with sera from cystic-fibrosis homozygotes than from heterozygotes, suggesting the possibility of a new quantitative biochemical assay for cystic fibrosis.