The isolation and the biochemistry of the animal protein factor

Investigators are generally convinced by now that the animal protein factor is vitamin-Iike in nature. Experiments which have supplied the data for this report were initiated mainly for the purpose of isolating, purifying, and concentrating the animal protein factor, and to determine by biological means some of the chemical and physical properties of this vitamin-like substance. Fish solubles were used. The fuller's earth eluate was broken down into various fractions, and these fractions were fed to chicks in order to determine the completeness by which each fraction was purified and the biological value of each fraction.