SDS-polyacrylamide gel electrophoretic analysis of high molecular mass glycoproteins from human milk fat globules revealed that the pattern of bands is unique for each milk donor. The number, position, width and intensity of bands varied between donors. A difference in the pattern of sisters could be discerned. There is evidence that these mucin-like glycoproteins, which originate from the plasma membrane of the mammary epithelial cell, occur in other cells and tissues. They may function in the immunorecognition system because of their individual-specific character and cell surface location.
