Particle-labelled immunoassays: a review.

Up to now, various types of particles have been used as labels in immunoassay. Well known examples are erythrocytes and latex particles. More recently, colloidal gold and dye particles have been introduced as a label.

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.