Cetrimide Agar is primarily used in microbiology for the selective isolation and cultivation of Pseudomonas aeruginosa from clinical, environmental, and pharmaceutical samples. The medium inhibits the growth of most other bacteria and fungi due to the presence of cetrimide, a quaternary ammonium compound, allowing P. aeruginosa to grow selectively. This bacterium produces characteristic pigments—such as water-soluble blue-green pyocyanin and yellow-green fluorescein—making it easily identifiable on the agar. The agar is commonly used in hospitals to detect P. aeruginosa in wound, burn, and urine specimens. It is also employed in water and cosmetic product testing to ensure sterility and detect contamination. Due to its specificity, Cetrimide Agar is a standard tool in both clinical diagnostics and quality control laboratories.