Potassium tellurite, in association with agar is used as a selective medium for growth of clauberg (bacteria). It is used for the selective isolation of staphylococci and corynebacteria, which is used to reduce TeO₃ ^2- to tellurium element.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.