[A micromethod for the determination of N-acetylneuraminic acid in glycoproteins (author's transl)].

a micromethod is described for the determination of free or glycoprotein-bound N-acetylneuraminic acid (NANA) on the basis of oxidation with periodic acid and reaction with thiobarbiturate. When using athe Eppendorf microliter system the method is easy to perform, the lowest level of sensitivity being 0.2 nmoles NANA in the incubation mixture. The intraassay precision comprises 3.0% CV, the interassay precision 4.3% CV. The accuracy of the results obtained by this micromethod was proved by comparative experiments with the macromethod according to Warren ((1959), J. Biol. Chem. 234, 1971-1979) using sialyllactose, transferrin and fibrinogen as reference materials.