Reagents are chemical or biological substances used in laboratory and manufacturing processes to detect, measure, produce, or transform other substances. In biopharmaceutical manufacturing and quality control, reagents include buffers, enzymes, antibodies, standards, calibrators, and assay components used in analytical testing, process development, and GMP production. Critical reagents — such as reference standards, critical assay reagents (CARs), and biological reagents — must be rigorously qualified, characterized, and controlled to ensure the reliability, reproducibility, and regulatory compliance of analytical methods and batch release activities.
