Abstract: On many kinds of solid substrate, such as polyamide membrane, cellulose acetate membrane etc., the specific immunological reaction between the human immunoglobulin G(IgG) and the goat anti human antibody labeled with isothiocyanate fluorescein(GAHAb ^*) can be carried into practice quantitatively. The antigen antibody conjugate remained excellent room temperature phosphorescence(RTP) properties of isothiocyanate fluorescein. The conditions for immunological reaction and RTPmeasurement were optimized. Aconvenient solid substrate room temperature phosphorescence immunoassay(SS-RTP-IA) method for determination of the IgGhas been developed. The linear dynamic range of the method is 0.624-20 pg/spot(0.4μL) and the calculated detection limit by the methodology of IUPACis 0.32 pg/spot. The regression equation is ΔI_p=31.4+46.2 lg[ c (Ag)/pg], correlation coefficient r=0.999, n=6. The method was used for the determination of Ig Gin normal human serum with good satisfactory results. The analytical recoveries are 96%-104% for seven replicates and the relative standard deviations are 2.6%-2.9%.

Key words: Solid substrate room temperature phosphorescence-immunoassay, Human IgG, GAHAb