Detection limit estimated from slope of calibration curve: an application to competitive ELISA.
This paper theoretically derives a general rule that while the slope of the semi-logarithmic plot (Y vs. log X) of a calibration curve varies depending on analyte concentration, X, the slope takes a specific value at the detection limit (L(D)). This rule holds good irrespective of the shape of the calibration curve (linear or non-linear) and in this paper, is applied to competitive ELISA (enzyme linked immunosorbent assay). The following relationship is deduced: slope of log-dose B/B0 at L(D) = [relative standard deviation (RSD) of blank responses] / 0.13. The L(D) obtained from the above-mentioned slope corresponds to the dose at which the RSD of dose estimates is 0.3 (= 30%). A commercial kit for 17alpha-hydroxyprogesterone is taken as an example.
Hayashi
Yuzuru
Y
National Institute of Health Sciences, 1-18-1 Kami-Yoga, Setagaya, Tokyo 153-8501, Japan.
Matsuda
Rieko
R
Ito
Katsutoshi
K
Nishimura
Waka
W
Imai
Kazuhiro
K
Maeda
Masako
M
D019326:17-alpha-Hydroxyprogesterone / Q000032:analysis; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D016015:Logistic Models; D008956:Models, Chemical; D012680:Sensitivity and Specificity
D019326:17-alpha-Hydroxyprogesterone