What kind of test uses antibodies to detect the presence of drugs?

Immunoassays are a type of test that utilize the specific binding properties of antibodies to detect the presence of drugs or their metabolites in a sample. These tests are based on the principle of antigen-antibody interaction, where antibodies specifically bind to the target substance—such as drugs—allowing for their detection and quantification.

Immunoassays can be further categorized into various formats, such as enzyme-linked immunosorbent assays (ELISAs), radioimmunoassays, and fluorescent immunoassays, each differing in the detection method but maintaining the core principle of antibody-based detection. Their high sensitivity and specificity make them a preferred method in clinical laboratories for drug screening.

Other options, like bacterial cultures, serum tests, and enzyme assays, do not primarily rely on antibodies for their testing processes. Bacterial cultures are aimed at isolating and identifying bacterial pathogens, serum tests may refer to a variety of blood tests that could measure different components but are not exclusively drug tests, and enzyme assays typically measure enzyme activity rather than the presence of drugs. Thus, immunoassays are specifically designed for drug detection using antibodies, making this option the most accurate choice.