Stable antigenic extracts methods

摘要

A storage-stable, high potency allergenic extract is prepared by ultrafiltration, retaining fractions having molecular weights of from 1000 to 100,000, and drying the retained fraction to a moisture content of less than one weight percent. The extract can also be pretreated with amylase before ultrafiltration, treated with affinity chromatography before drying, and/or treated with gamma radiation after drying.