Simple colorimetry of glycated serum protein in a centrifugal analyzer.
A recently described (Clin Chim Acta 127: 87-95, 1982) colorimetric assay for glycated proteins in serum exploits their ketoamine activity to reduce 3,3'-(3,3'-dimethoxy-4,4'-biphenylylene)bis [2-(p-nitrophenyl)-5-phenyl-2H-tetrazolium chloride] (nitroblue tetrazolium) in alkaline solution; the authors termed this the "fructosamine assay." The method is simple, requiring only the addition of one reagent and measurement of the absorbance change during 5 min; results are expressed relative to a synthetic standard. We have adapted this for use in a centrifugal analyzer and report its performance, both analytically and as an index of hyperglycemia. Precision is good (between-batch CV 2.1%), the reagent is stable and inexpensive, and the procedure is rapid (75 samples per hour). Albumin influences the measurement, but for concentrations greater than or equal to 35 g/L this was not a serious problem. Normal and diabetic populations can be clearly discriminated (p less than 0.001). The test detected 25 (84%) of the 30 untreated diabetics studied and gave four false positives (8%). The results correlate well with those for glucose in plasma of fasting subjects (r = 0.87) and for hemoglobin A1 (r = 0.80).
D000328:Adult; D000368:Aged; D001322:Autoanalysis; D001798:Blood Proteins / Q000032:analysis*; D002498:Centrifugation; D003124:Colorimetry; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D019270:Fructosamine; D006023:Glycoproteins; D006595:Hexosamines / Q000097:blood*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D013053:Spectrophotometry; D000093422:Glycated Serum Proteins
D001798:Blood Proteins; D006023:Glycoproteins; D006595:Hexosamines; D019270:Fructosamine; D000093422:Glycated Serum Proteins