blastocystin

Blastocystin is not a standard term in current scientific nomenclature. In practice, it most commonly refers to blasticidin S, a nucleoside antibiotic produced by Streptomyces species and used as a selective agent in cell culture. The name blastocystin may appear as a mis-spelling or variant of blasticidin.

Blasticidin S inhibits protein synthesis by interfering with the ribosome. It binds to the peptidyl transferase center, effectively blocking translation elongation and, in many contexts, leading to halted growth of susceptible cells. The compound is active against a range of organisms and is particularly utilized for selectively killing non-resistant cells in culture systems.

In laboratory settings, cells are made resistant through the blasticidin resistance gene (bsd). Blasticidin S is typically applied to mammalian cell cultures at low microgram-per-milliliter concentrations (for example, a few to several µg/mL, depending on cell type and construct). For routine work, blasticidin is often used in conjunction with appropriate negative controls and validated resistance constructs.

Natural production and chemistry: Blasticidin S is a secondary metabolite produced by certain Streptomyces strains. In research use, it is commonly supplied as blasticidin S hydrochloride, a salt form that improves stability and handling.

Safety and regulation: Blasticidin is toxic and irritant. It is intended for in vitro use only and requires appropriate laboratory safety practices, including personal protective equipment and waste disposal in accordance with institutional guidelines.

See also: blasticidin resistance, BSD gene, antibiotic selection systems.