Tetracycline is a polyketide antibiotic produced by Streptomyces spp. It inhibits protein synthesis by binding to 30S ribosomal subunit and blocking attachment of charged aminoacyl tRNA to ribosome. This prevents incorporation of new amino acids to the nascent peptide chain. It acts as a broad spectrum antibiotic against Grampositive and Gram-negative bacteria.
In cell culture media, Tetracycline finds application as an anti-bacterial agent to prevent contamination. It is also used as a selection agent for cells containing tetracycline resistance gene. Besides this, Tetracyclinebased externally regulated (Tet-based) systems have been successfully used to control the expression of numerous transgenes in cultured cells. These systems
work on principle of reversible switch-on-switch-off of the experimental gene in presence of Tetracycline. These are tightly regulated and highly responsive systems that produce on-demand robust expression of gene of interest in target cells. During such Tet-system based mammalian cell culture studies, an animal-free media is to be used for cell growth and to prevent any interference from excess tetracycline present in media.