A METHOD AND APPARATUS FOR LIGAND DETECTION

摘要

A process and apparatus has been developed for radioassay of ligand in solution which eliminates the separation step required in conventional techniques. A chamber (10) is provided containing a quenching solution (22), a plurality of ligand molecules (LM) and a plurality of receptor molecules (R). One of pluralities forms a free species labelled with a beta particle emitter (LM*) while the other is immobilized on a solid support (16), e.g., the chamber wall or a microbead, within the chamber (l0). Ligand (L) introduced with the sample competes with ligand molecules (LM) already in the chamber for receptor sites on the receptor molecules (R) and the free species is allowed to diffuse about the chamber (10). A beta particle detector (14) in communication with the chamber (10) at a fixed position detects only those beta particles omitted from within the quenching distance of the quenching solution (22). The quenching properties of the solution (22) are used in place of the conventional separation step. The process and apparatus are easily adapted for continuous monitoring of ligand level and are particularly well suited for use in radioimmunoassays. The apparatus can be miniaturized allowing implantation in an animal body and in vivo monitoring of ligand level in bodily fluids.