A solid-phase immobilized epitope immunoassay (SPIE-IA) permitting very sensitive and specific measurement of angiotensin II in plasma.
We have developed a new enzyme immunometric assay for angiotensin II (AII) based on SPIE-IA technology (solid-phase immobilized epitope-immunoassay). A monoclonal antibody with optimal properties (mAb3 131) was selected from a series of 19 anti-AII mAbs. The mAb had to be purified from ascitic fluid in a specific manner in order to remove endogenous AII from the antibody-binding sites. We established a sensitive (minimum detectable concentration 0.5 pg/ml) and precise (CV below 15% in the 2-100 pg/ml range) SPIE-IA. Using different AII-related peptides, we observed that this new assay has a specificity profile that compares favourably with the corresponding competitive immunoassay. We have used the assay to measure AII in 42 plasma samples, and demonstrated a good correlation with values obtained using a commercial radioimmunoassay. Assay specificity was supported by HPLC fractionation experiments, confirming the absence of interference induced by endogenous AII-related products.
Volland
H
H
SPI-BIO, 2 rue du Buisson aux Fraises, Z.I. de la Bonde, F-91741 Massy Cedex, France.
Pradelles
P
P
Ronco
P
P
Azizi
M
M
Simon
D
D
Créminon
C
C
Grassi
J
J
D000110:Acetylcholinesterase; D000595:Amino Acid Sequence; D000804:Angiotensin II / Q000031:analogs & derivatives / Q000097:blood* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal; D002851:Chromatography, High Pressure Liquid; D000939:Epitopes; D005069:Evaluation Studies as Topic; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods* / Q000706:statistics & numerical data; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D000939:Epitopes; D000804:Angiotensin II; D000110:Acetylcholinesterase