Chlortetracycline-13C,d3 hydrochloride (7-Chlorotetracycline-13C,d3 hydrochloride) is the 13C- and deuterium labeled Chlortetracycline hydrochloride. Chlortetracycline hydrochloride is an orally active, selective antibiotic , that inhibits methanogenic bacteria through inhibition of bacterial protein synthesis. Chlortetracycline hydrochloride is a specific and potent calcium ionophore antibiotic , that inhibits binding of aminoacyl-tRNA to ribosomes.