Research Area: Infection Biological Activity: Tetracycline hydrochloride is a hydrochloride salt of tetracycline that is a broad-spectrum polyketide antibiotic. Tetracycline binds to the 30S subunit of microbial ribosomes. Tetracycline inhibits protein synthesis by blocking the attachment of charged aminoacyl-tRNA. Thus tetracycline prevents introduction of new amino acids to the nascent peptide chain. The action is usually inhibitory and reversible upon withdrawal of the drug. Resistance to the tetracycline results from changes in permeability of the microbial cell envelope. In susceptible cells, the tetracycline is concentrated from the environment and does not readily leave the cell. In resistant cells, the drug is not actively transported into the cell or leaves it so rapidly that inhibitory concentrations are not maintained. Tetracycline hydrochloride is used in the treatment of bacterial infections, such as urinary tract infections, acne, gonorrhea, chlamydia, and others.[1]References on Tetracycline HCl[1] http://en.wikipedia.org/wiki/Tetracycline, ,