Czapek Dox Agar is a semisynthetic medium containing sodium nitrate as the sole source of nitrogen. It is used for the for the routine cultivation of fungi, especially Aspergillus, Penicillium, and non-sporulating molds. Czapex Dox Agar medium is used for the cultivation of those fungi and bacteria that are able to utilize sodium nitrate as the sole source of nitrogen.

This medium can also be used for chlamydospore production by Candida albicans. The medium has good buffering action due to the presence of different salts. Czapek Dox Agar supports abundant growth of almost all saprophytic Aspergilli with characteristic mycelia and conidia formation.

Sucrose serves as the only source of carbon while sodium nitrate serves as the sole source of nitrogen. Dipotassium phosphate buffers the medium. Magnesium sulphate, potassium chloride, and ferrous sulphate are included as essential ions necessary for growth.