Purity >95%. Oxytetracycline is a broad-spectrum tetracycline antibiotic that inhibits protein synthesis in both Gram-positive and Gram-negative bacteria. The features of its biosynthesis often serve as a representative example for understanding the synthesis of other type II polyketides. Oxytetracycline is also used to examine the acquisition of oxytetracycline-resistance genes, which are associated with the development of antibiotic resistance.