Oxytetracycline hydrochloride is a salt prepared from oxytetracycline taking advantage of the basic dimethylamino group which protonates readily to form the salt in hydrochloric acid solutions. The hydrochloride is the preferred formulation for pharmaceutical applications. Like all tetracyclines, oxytetracycline shows broad spectrum antibacterial and antiprotozoan activity and acts by binding to the 30S and 50S ribosomal sub-units, blocking protein synthesis.Oxytetracycline is a tetracycline analog isolated from the actinomycete Streptomyces rimosus. Oxytetracycline is an antibiotic indicated for treatment of infections caused by Gram positive and Gram negative microorganisms such as Mycoplasma pneumoniae, Pasteurella pestis, Escherichia coli, Haemophilus influenzae, and Diplococcus pneumoniae. It is used in studies on the oxytetracycline-resistance gene (otrA). Oxytetracycline hydrochloride is used to study phagosome-lysosome (P-L) fusion in P388D1 cells and antibiotic susceptibilities of Mycoplasma bovis isolates.