A Practical laboratory Preparation of Avidin Concentrates for Biological Investigation

Abstract

Avidin concentrates are prepared by precipitation of the active fraction during a dialysis (in distilled water) of a 1% saline extract of an acetone coagulation of dried egg white solution at pH 5.1. The activity of these preparations (1.5 units/mg ) averages 20% that of "pure" (8.0 units/mg ) avidin, and the yield is about one g of such material from 800 g of dried egg white. The avidin activity is determined by microbiological assay with Saccharomyces cerevisiae ATCC-9896 from American Type Culture Collection, Washington, D. C.