Tetracycline is a broad spectrum polyketide antibiotic with clinical uses in treating bacterial infections such as Rocky Mountain spotted fever, typush fever, tick fevers, Q fever, and Brill-Zinsser disease and to treat upper respiratory infections and acne. It has been used in studies of multidrug resistance and potential side effects including acute pancreatitis. It is recommended for use in cell culture applications at 10 mg/L.

Mode of Action: Tetracycline passively diffuses through proin channels in the cell membrane, binding to 30S ribosomes and inhibits protein synthesis by preventing access of aminoacyl tRNA to the acceptor site on the mRNA-ribosome complex. It also binds to the bacterial 50S ribosomal subunit, altering the membrane and causing intracellular components to leak from bacterial cells. The inhibitory effects can be reversed by washing, suggesting that it is the reversibly bound antibiotic, and not the irreversibly bound drug, that is responsible for antibacterial action.

Mode of Resistance: The effects are inactivated via a loss of cell wall permeability.

Antimicrobial spectrum: Includes a wide range of antimicrobial activity against gram-positive and gram-negative bacteria.