ATCC's Mycology and Botany Collection houses over 27,000 strains of filamentous fungi and yeast distributed among 1,500 genera and 7,000 species. The Botany Collection also contains over 400 strains of patented seeds. The collection catalog is divided into three subcollections. Please choose the appropriate one to find the strains you need. To search specifically for genetically defined Saccharomyces cerevisiae and deletion mutants, go to the Yeast Genetic Stock Center.