One-step all-in-one dry reagent immunoassays with fluorescent europium chelate label and time-resolved fluorometry.
The availability of an intrinsically fluorescent, inert, and stable Eu chelate label made it feasible to design one-step all-in-one immunoassays with time-resolved fluorometry for detection. Both competitive and noncompetitive immunoassays are performed in microtitration wells containing all assay-specific components in a stable dry form. Only the sample and one assay buffer common for all analytes need to be added. Model assays for human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and progesterone all reached equilibrium in 15 min or less without compromising the performance characteristics of the measurements, all of which perform at least equivalent to state-of-the-art assays. The detection limits for hCG, AFP, and progesterone were 0.3 IU/L, 0.1 microgram/L, and 0.5 nmol/L, respectively. The assay ranges for hCG and AFP were linear to 5000 IU/L and 1200 micrograms/L, respectively. The immunoassay format can be readily implemented in a fully automated random-access immunoassay system with optimal performance characteristics and no handling of analyte-specific assay components.
Lövgren
T
T
Department of Biotechnology, University of Turku, Finland. timo.lovgren@utu
Meriö
L
L
Mitrunen
K
K
Mäkinen
M L
ML
Mäkelä
M
M
Blomberg
K
K
Palenius
T
T
Pettersson
K
K
D001667:Binding, Competitive; D006063:Chorionic Gonadotropin / Q000097:blood; D005063:Europium; D005456:Fluorescent Dyes; D015200:Fluoroimmunoassay / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007202:Indicators and Reagents; D007700:Kinetics; D011374:Progesterone / Q000097:blood; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000032:analysis
D006063:Chorionic Gonadotropin; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D000509:alpha-Fetoproteins; D005063:Europium; D011374:Progesterone