Abstract
A stable antigen was developed for the indirect fluorescence test for Trichinella spiralis antibodies. The antigen was prepared by digesting fresh larvae of T. spiralis with pepsin for 36 hr and fixing the cuticle in 10% formol-0.5% bovine serum albumin. The antigen can be stored for several months without loss of activity or specificity. Evidence is advanced to support the hypothesis that specific antigenic sites are a constituent part of the larval cuticle.