Quantification of human apolipoprotein A-IV by "sandwich"-type enzyme-linked immunosorbent assay.
A specific and sensitive "sandwich"-type enzyme-linked immunosorbent assay (ELISA) has been developed for quantifying human apo A-IV. Using apo A-IV immunosorbent columns, we isolated monospecific anti-apo A-IV antibodies for coating the ELISA plates and for preparing peroxidase-antibody conjugate. The assay can detect as little as 0.20 ng of apo A-IV, with mean intra- and interassay CVs of 3.6% and 8.2%, respectively. The apoA-IV concentrations in normolipemic and hyperlipemic plasma were unaffected by either delipidation or treatment with detergents or urea. To validate the ELISA assay we compared it with an immunoelectrophoretic technique. ApoA-IV concentrations in plasma from normo- and dyslipemic subjects compared well by the two assays (r = 0.89). The mean apo A-IV concentration, measured by ELISA in plasma from 50 normolipemic subjects, was 143 (SD 52) mg/L; values for dyslipemic subjects were not significantly different. We also used this new assay to monitor apo A-IV profiles of normolipemic and hypertriglyceridemic plasma after chromatographic fractionation.
Rosseneu
M
M
Department of Clinical Chemistry, A.Z. St-Jan, Ruddershove, Brugge, Belgium.
Michiels
G
G
De Keersgieter
W
W
Bury
J
J
De Slypere
J P
JP
Dieplinger
H
H
Utermann
G
G
D001054:Apolipoproteins A / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D013048:Specimen Handling
D001054:Apolipoproteins A; C022205:apolipoprotein A-IV