Which section is primarily used to measure hormones, enzymes, and drugs?

• A. Chemistry
• B. Immunochemistry
• C. Hematology
• D. Serology

Answer: (B)

Immunochemistry relies on antibody-antigen interactions to detect and quantify substances in patient samples. This approach is ideal for measuring hormones and many drugs because immunoassays can achieve high sensitivity and specificity even when targets are present at very low levels. Hormones are often circulating in small amounts, and antibodies can selectively bind them to produce a measurable signal. Drugs, including therapeutic and illicit substances, are routinely measured with these same antibody-based methods because they can detect small molecules efficiently and are readily automated for clinical use. Some enzymes are also quantified this way when the goal is to measure the enzyme protein itself or specific isoforms rather than assessing its catalytic activity; in such cases, antibody-based assays provide precise, rapid results. For these reasons, this section of the lab focuses on immunochemistry to measure hormones, enzymes, and drugs. In contrast, chemistry typically analyzes analytes through direct chemical reactions, serology centers on infectious-disease antibody/antigen testing, and hematology handles blood cells and coagulation.