A Magnetic Nanoparticle-Based Time-Resolved Fluoroimmunoassay for Determination of the Cytokeratin 19 Fragment in Human Serum

A time-resolved fluoroimmunoassay to assay the rabies virus glycoprotein: application for estimation of human rabies vaccine potency

Replacement of the in vivo rabies vaccine potency test (NIH test) by in vitro methods had been discussed by several researcher including WHO expert working groups. In this paper, a time-resolved fluoroimmunoassay (TRFIA) for the assay of rabies virus glycoprotein in rabies vaccine was first established to estimate the rabies vaccine potency by using specific monoclonal antibody that only recognized the native, trimeric and immunogenic form of rabies virus glycoprotein. Potency of the rabies virus glycoprotein was assayed with satisfactory performance under optimal conditions, and the method demonstrated satisfactory results when applied in practical samples. The correlation coefficient of potency values obtained from the present TRFIA and ELISA was 0.912, and 0.903 for those from the present TRFIA and NIH test. These preliminary results confirmed that this TRFIA can replace ELISA with higher performance, and could be a promising replacement of the NIH test. Based upon these results, the present TRFIA seemed to be a convenient tool for evaluating rabies vaccine potency and its products at different stages accordingly.

Rapid quantitation of human epididymis protein 4 in human serum by amplified luminescent proximity homogeneous immunoassay (AlphaLISA)

A sensitive, rapid and homogeneous reaction measurement method for quantitation of human epididymis protein 4 (HE4) in human serum by amplified luminescent proximity homogeneous immunoassay (AlphaLISA) was described. Built on a sandwich-type immunoassay format, analytes in samples were captured by one biotinylated monoclonal antibody combining on the surface of streptavidin coated donor beads, and "sandwiched" by another monoclonal antibody coated on acceptor beads. The coefficient variations of the method were lower than 10%, and the recoveries were in the range of 90-110% for serum samples. A value of 0.88pmol/l was identified as the minimum detectable dose of the present method for HE4. Compared with the results from electrochemiluminescence immunoassay kit (Roche) in 170 serum samples, there was a satisfied correlation coefficient of 0.984. The present assay demonstrated high sensitivity, wider effective detection range and excellent reproducibility for quantitation of HE4 can be useful for early screening and prognosis evaluation of patients with ovarian cancer.