Biochem/physiol Actions Mode of Action: Inhibits protein synthesis (elongation) by preventing binding of aminoacyl-tRNA to the 30S subunit. Antimicrobial spectrum: Gram-negative and Gram-positive bacteria.Mode of Resistance: Loss of cell wall permeability. Tetracycline inhibits bacterial protein synthesis elongation at the level of aminoacyl-tRNA binding to the 30S ribosome. Tetracycline passively diffuses through porin channels in the bacterial cell membrane. It also binds to the bacterial 50S ribosomal subunit which may alter the cytoplasmic membrane, causing intracellular components to leak from bacterial cells1. Mode of resistance is loss of cell wall permeability. Application Tetracycline is a broad spectrum polyketide antibiotic. It is used clinically to treat bacterial infections such as Rocky Mountain spotted fever, typhus fever, tick fevers, Q fever and Brill-Zinsser disease. It is used to treat upper respiratory infections and acne1. It is used to study multidrug resistance2 as well as potential side effects such as acute pancreatitis3. It has been used in target and resistance based mechanistic studies of novel antibiotics4. Protocols & Applications Antibiotic Selector for application, solubility, solution stability, working concentration, and mode of action information