Optimization of a sandwich sol particle immunoassay for human chorionic gonadotrophin.

Colloidal gold particles coated with rabbit anti-HCG (Au-(anti-HCG)) were used in a spectrophotometric 'sandwich' SPIA for HCG. The effects of several reagent properties and assay variables were investigated in order to optimize the assay. Best results were obtained with 55 nm particles.

A homogeneous sol particle immunoassay for total oestrogens in urine and serum samples.

Conjugates prepared by adsorption of antibodies to colloidal gold particles were used in a homogeneous sol particle immunoassay for total oestrogens. The assay is based on inhibition by free oestrogens in the sample of the agglutination of a reaction mixture, consisting of the sample, the gold particle anti-oestriol conjugate and a suitable amount of oestriol-16/17-monosuccinyl-bovine serum albumin. The effect of different assay conditions is discussed.

A homogeneous sol particle immunoassay for human chorionic gonadotrophin using monoclonal antibodies.

A mixture of monoclonal antibodies against human chorionic gonadotrophin (HCG) from 2 different clones was used to develop a homogeneous sol particle immunoassay (SPIA) for HCG, with high discrimination against luteinizing hormone (LH). The optimization of this assay is described. The work resulted in a spectrophotometric and a visual reading version.

A sol particle agglutination assay for human chorionic gonadotrophin.

Conjugates, prepared by adsorption of antibodies on colloidal gold particles, were used in a homogeneous sol particle immunoassay (SPIA) for human chorionic gonadotrophin (HCG). The technique is based on sol particle agglutination, resulting in colour reduction. Optimal results were obtained using buffered conjugates prepared from 50 nm particles.

Sol particle immunoassay (SPIA).

We describe the use of inorganic (metal) colloidal particles as a label for immunoassays. Dose-response curves for human placental lactogen (HPL) and human chorionic gonadotrophin (HCG) were obtained with sandwich immunoassays, using conjugates consisting of antibody-coated colloidal gold or silver particles. Several techniques were used to measure the amount of bound conjugate, viz.