Sodium tellurite is a chemical compound with the formula Na2TeO3. It appears as a white or yellowish powder and is primarily used in laboratories and industrial applications. Sodium tellurite is known for its role as a source of tellurite ions, which can be utilized in various chemical reactions and processes. In biological contexts, sodium tellurite has been studied for its effects on microorganisms. It can act as an antimicrobial agent, inhibiting the growth of certain bacteria. Additionally, it is sometimes used in the preparation of culture media for microbiology research, helping to isolate specific types of bacteria.