Studies on the constitution of casein.

Probably no single protein has been the subject of as many chemical investigations as has casein. This is to be expected since casein is the main protein constituent of the milk of all mammals and because it can be readily isolated in a more or less pure state and with reasonably reproducible properties. For one hundred years following Mulder’s discovery that casein may be precipitated from milk by the addition of acid, casein was considered the typical example of a homogeneous protein. It was not until the classical solubility studies of Linderstrom-Lang were published, that casein was definitely shown to be a mixture of proteins