Patent ID: 8293492

Claim:
An Immunoassay for detecting thalidomide in a sample comprising providing a mixture containing said sample, an antibody being selectively reactive with mixture of the pharmaceutically active chemotherapeutic drugs lenalidomide and thalidomide and having a reactivity with thalidomide of at least 10% based upon its reactivity with said mixture of pharmaceutically active chemotherapeutic drugs and a conjugate of a carrier with a ligand having the formula: wherein B is —C(═O)—CH2-, —C(═O)—NH—CH2-, —C(═O)—O—CH2- or —CH2- Y is an organic spacing group; p is an integer from 0 to 1; and X is a terminal functional group capable of binding to a carrier; causing the thalidomide in said sample and said conjugate to bind with said antibody and thereafter measuring the said conjugate in said mixture that is bond or unbound to said antibody, whereby the presence of thalidomide in said sample can be detected.