Widely used in cell culture laboratories to prevent bacterial contamination. It is added to cell culture media to inhibit the growth of both gram-positive and gram-negative bacteria. Commonly used in mammalian cell cultures, primary cell isolations, and tissue culture work where sterility is critical. The combination provides broad-spectrum antibiotic coverage, making it effective during routine subculturing, thawing frozen stocks, and when handling cells outside of fully sterile environments. Often used prophylactically, though not recommended for long-term use to avoid potential cytotoxic effects or masking low-level contamination.