Clinical biochemistry (clinical chemistry) measures chemicals in blood and other fluids—things like glucose, urea, liver enzymes, lipids and electrolytes—to help doctors understand a patient’s health. Spectrophotometry in simple words Most chemistry tests are spectrophotometric. The idea is straightforward: Reagent + Sample → Color/Light change. When the patient sample reacts with a reagent, the mixture changes how it absorbs light at a specific wavelength. Shine light → Mea

Electrochemiluminescence (ECL) is a lab method where a small voltage makes special labels on antibodies emit light, and the instrument measures that light to quantify the target in the sample. Why labs like it Very sensitive and precise for low concentrations Wide measuring range, fewer dilutions Fast & stable reagents, reliable calibration on Elecsys/ECLIA platforms How a Roche ECL immunoassay works Sample mixes with antibodies (one carries a light-emitting ruthenium label;