Enzymatic assay of serum sialic acid.
Serum sialic acid has been assayed enzymatically. The reaction includes neuraminidase hydrolysis of glycoprotein, cleavage of sialic acid to pyruvate by N-acetyl neuraminic acid (NANA)-aldolase, oxidation of pyruvate by pyruvate oxidase which produces hydrogen peroxide, and colorimetry of hydrogen peroxide using the peroxidase-p-chlorophenol-4-amino-antipyrine method. This method showed good correlation between a chemical method (r = 0.984), good recovery (98.8%) and good reproducibility (within-run-precision: 1.0% C.V.; day-to-day precision: 1.9% C.V). Intrinsic serum pyruvate produces an equimolar positive effect. The normal value range is 1.94 +/- 0.29 mmol/l (mean +/- S.D.,n = 24).
D055598:Chemical Phenomena; D002621:Chemistry; D005260:Female; D006801:Humans; D008297:Male; D008722:Methods; D009439:Neuraminidase; D007652:Oxo-Acid-Lyases; D012016:Reference Values; D012794:Sialic Acids / Q000097:blood*
D012794:Sialic Acids; D009439:Neuraminidase; D007652:Oxo-Acid-Lyases; C018728:N-acetylneuraminate lyase