Measurement of unsaturated ""granulocyte-related'' (TC I and TC III) and ""liver-related'' (TC II) B12 binders by instant batch separation using a microfine precipitate of silica (QUSO G32).

A microfine precipitate of silica (Quso G32) almost instantly quantitatively adsorbs the polypeptide transcobalamin II from serum without adsorbing the glycoproteins transcobalamins I and III. This provides a simple, rapid, and reproducible method for the measurement of the granulocyte-related transcobalamins I and III and the liver-related transcobalamin II in serum, and is also applicable to their purification, and the separation and purification of other polypeptide-glycoprotein mixtures.