A specificity-enhanced time-resolved fluoroimmunoassay for zeranol employing the dry reagent all-in-one-well principle.
A simple dry chemistry time-resolved fluorescence immunoassay (TR-FIA) method was developed for the measurement of zeranol in bovine urine samples. The samples were purified by immunoaffinity chromatography and a specificity-enhanced zeranol antibody was employed in the immunoassay. This resulted in a highly selective method, which had only negligible reactivity with Fusarium spp. toxins. The all-in-one-well dry chemistry concept made the assay very simple to use because all the assay-specific reagents were already present in the reaction wells in dry form. Only the addition of diluted sample extract was required to perform the competitive one-step TR-FIA and the results were available in less than 1 h. The analytical limit of detection (mean + 3s) for the immunoassay was 0.16 ng ml(-1) (n = 12) and the functional limit of detection for the whole method, estimated by the analysis of zeranol-free samples, was 1.3 ng ml(-1) (n = 20). The recovery of zeranol at the level of 2 ng ml(-1) was 99% (n = 18) and the within-assay variation ranged between 4.5 and 9.0%.
Tuomola
Mika
M
Department of Biotechnology, University of Turku, Finland. mika.tuomola@utu.fi
Cooper
Kevin M
KM
Lahdenperä
Susanne
S
Baxter
G Andrew
GA
Elliott
Christopher T
CT
Kennedy
D Glenn
DG
Lövgren
Timo
T
D000818:Animals; D002846:Chromatography, Affinity; D004968:Estrogens, Non-Steroidal / Q000032:analysis* / Q000276:immunology; D005455:Fluorescent Antibody Technique; D007106:Immune Sera / Q000302:isolation & purification; D011817:Rabbits; D015029:Zeranol / Q000032:analysis* / Q000276:immunology
D004968:Estrogens, Non-Steroidal; D007106:Immune Sera; D015029:Zeranol