Formaldehyde treated gelatin as a gel exclusion agent.

A high molecular weight fraction of gelatin precipitated from a solution of Difco gelatin with polyethylene glycol has several favourable properties in gel exclusion chromatography. To manufacture the gel exclusion agent, the gelatin was dissolved in hot water, allowed to set in the cold and rendered insoluble by reaction with formaldehyde. When finely disrupted and used as bed material in columns this gel is capable of separating protein components from mixtures of proteins of widely different molecular weights. Favourable properties include elasticity at relatively low concentration, its availability and its inexpensive nature.