Determination of α-Lactalbumin in Complex Systems

A simple method based on an immunological procedure has been devised to quantitate accurately the amount of a-laetalbumin present in complex systems including milk and milk products.The method is based on the rate of diffusion in a small tube of a-lactalbumin into a layer of agar containing antisera to the a-lactalbumin.The techniques were originally described by Oudin and recently adapted in this laboratory for the quantitative determination of ~-lacteglobulin in similar complex systems.The usable range of the method is about 6 to 80 t~g/ml of a-laetalbumin.Milk contains about 1,000 to 1,500 tLg/ml of a-lactalbumln; thus, dilution is the only sample preparation required for milk and milk products.A concentration procedure has also been devised with which it has been possible to determine less than 1 ~g/m] of a-laetalbumin in complex solutions containing high levels of blood and other cellular proteins.