In immunoassays for therapeutic drug monitoring, which description matches Microparticle Enzyme Immunoassay?

• A. Microparticle Enzyme Immunoassay
• B. Enzyme Multiplied Immunoassay Technique
• C. Fluorescence Polarization Immunoassay
• D. Enzyme-Linked Immunosorbent Assay

Answer: (A)

Microparticle Enzyme Immunoassay describes a method that uses antibody-coated microparticles and an enzyme-based readout to measure drug levels. In therapeutic drug monitoring, this approach provides rapid, automated results by detecting the drug through a competitive binding reaction that yields an enzymatic signal. The name itself matches the technique precisely, distinguishing it from other formats: EMIT (Enzyme Multiplied Immunoassay Technique) uses enzyme-labeled reagents but not microparticles; fluorescence polarization immunoassay relies on fluorescence polarization rather than an enzyme signal; ELISA is a plate-based assay with a solid-phase solid support. So, the description that aligns with the method used in many TDM immunoassays is the Microparticle Enzyme Immunoassay.