Solid phase competitive binding assay - with sequential treatment of receptor with sample and tracer

摘要

Solid phase test comprises (a) contacting the sample with an appropriate receptor (R) carried on a solid support, then (b) removing the non-bonded anolyte (A) and (c) contacting (R) with a tracer (T) for (A). Pref. (T) is radioactivity labelled. (A) is esp. an antigen or a hapten and (R) is an antibody. Pref. (R) is contained inside a flow reactor through which the sample and then (T) are passed. Esp. non-bonded (T) and bonded (A) are then eluted so as to regenerate (R). Used specifically for analysis of thyroxin using radio-iodine labelled thyroxin as tracer, but also applicable to analysis of steroids, hormones, vitamins, etc. Improved sensitivity is achieved so that sample size can be reduced (for a given accuracy) or accuracy improved (for a given sample size).