Abstract

A method of detecting serum antinuclear factor by the use of antiglobulin conjugated with horseradish peroxidase has been compared with a standard procedure using a fluorescent label. The horseradish peroxidase conjugate was evaluated by block titration against positive serum and by its performance as a test reagent for screening and titrating sera. It is concluded that the horse-radish peroxidase method, in which an ordinary light microscope is employed, provides a satisfactory alternative to immunofluorescence for routine tests for antinuclear factor.