Sodium tellurite is a chemical compound with the formula Na2TeO3. It appears as a white or yellowish crystalline solid and is primarily used in laboratories and industrial applications. Sodium tellurite is known for its role in microbiology, where it serves as a selective agent for isolating certain bacteria. In addition to its use in microbiology, sodium tellurite has applications in the production of tellurium compounds and in the field of electronics. It can also be utilized in glass manufacturing and as a reagent in various chemical reactions. Safety precautions are necessary when handling this compound due to its potential toxicity.