Trichloroacetic acid (TCA) is widely used in analytical chemistry as a protein precipitating agent, particularly in sample preparation for biochemical assays. It effectively denatures proteins, allowing for the separation of proteins from other components in biological samples such as plasma or cell lysates. This makes TCA valuable in techniques like spectrophotometry and chromatography where clear, protein-free supernatants are required. In clinical and research laboratories, TCA is employed in the determination of serum uric acid, creatinine, and other metabolites by precipitating interfering proteins before analysis. It is also used in nucleic acid purification protocols to stabilize samples and remove contaminants. As a standard sample, TCA serves as a reference in quality control and method validation processes, ensuring consistency and accuracy in analytical measurements. Its well-defined properties make it suitable for calibration and standardization in titrimetric and spectroscopic methods. Additionally, TCA finds use in dermatology and cosmetic procedures as a chemical peeling agent, though the standard sample form is primarily intended for laboratory use rather than clinical application.