Characterization of alpha 1-microglobulin in human colostrum and milk.

The mean concentration of alpha 1-microglobulin in human colostrum and milk, estimated by electroimmunoassay, was found to be about 0.4-0.6 mg/l and 0.1-0.2 mg/l, respectively. Both liquids contained alpha 1-microglobulin in mono- and dimeric forms, while the presence of higher polymeric forms, as characterized in plasma, could not be demonstrated.