Quantitative determination of human plasma apolipoprotein A-I by a noncompetitive enzyme-linked immunosorbent assay.
A noncompetitive enzyme-linked immunosorbent assay (ELISA) for human plasma apolipoprotein A-I (ApoA-I) was developed. Microtiter plates were coated with purified antibodies to ApoA-I and blocked. Plasma samples from normolipidemic and hypertriglyceridemic subjects were added and ApoA-I was allowed to bind to coating antibodies. After washing, the amount of ApoA-I bound to microtiter plates was estimated with horseradish peroxidase-labeled antibodies to ApoA-I. A single step delipidization procedure was included to expose masked antigenic sites of ApoA-I in plasma. The average concentration of ApoA-I in plasma of normolipidemic subjects was 1.37 g/l. Recovery of ApoA-I added to plasma varied from 93-107%. Intra- and inter-assay coefficients of variations were 4 and 8%, respectively. The assay was also used for quantifying ApoA-I in lipoprotein density classes. There was a good correlation between this assay and electroimmunoassay (r = 0.84-0.92). The described sandwich ELISA is a specific, precise, sensitive and relatively simple method for measuring ApoA-I levels in human plasma.
D016632:Apolipoprotein A-I; D001053:Apolipoproteins / Q000097:blood; D001054:Apolipoproteins A / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D012016:Reference Values; D012737:Sex Factors; D013696:Temperature; D013997:Time Factors
D016632:Apolipoprotein A-I; D001053:Apolipoproteins; D001054:Apolipoproteins A