Quantification of apolipoprotein A-IV in human plasma by immunonephelometry.
We developed a nephelometric procedure for determining concentrations of human plasma apolipoprotein (apo) A-IV. Results obtained correlate well with those measured by an established electroimmunodiffusion assay (r = 0.98; n = 56). Intra- and interassay CVs were 2.4% and 2.0%, respectively, indicating excellent precision and reproducibility. Various conditions of sample treatment, such as adequate storage, freezing, and thawing, did not affect results significantly. However, keeping samples at room temperature for 4 days led to a slight increase in measured values. Preincubation with a cholesterinesterase-detergent mixture abolished interference from triglyceride-rich lipoproteins, allowing assay of samples containing triglycerides as great as 10 g/L. The assay is easily applicable to clinical laboratories for routine diagnostic use, as shown with hypertriglyceridemic plasmas and samples with a broad range of apo A-IV concentrations.
Schwarz
S
S
Zentrum Innere Medizin, Abteilung Endokrinologie und Stoffwechsel, University of Marburg, Germany.
Haas
B
B
Luley
C
C
Schäfer
J R
JR
Steinmetz
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001054:Apolipoproteins A / Q000032:analysis*; D016477:Artifacts; D002138:Calibration; D005260:Female; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D011309:Preservation, Biological; D012016:Reference Values; D015203:Reproducibility of Results; D014280:Triglycerides / Q000097:blood
D001054:Apolipoproteins A; D014280:Triglycerides; C022205:apolipoprotein A-IV