SD Growth Medium w/o HIS

Principle and Interpretation

SD Growth Medium w/o HIS is a synthetic defined agar media for the selective growth of Saccharomyces cerevisiae. Synthetically Defined media known as Yeast Nitrogen Base Media for the growth of Yeast cells were first cited by Wickerham (1, 2). SD Growth Medium w/o HIS includes a yeast nitrogen base along with ammonium sulfate, and dextrose as the carbon source, which is further supplemented with various amino acids except histidine which makes it a dropout growth medium for yeast cells. A histidine auxotrophic yeast mutant cannot grow on this media but a wild-type or a histidine prototrophic yeast strain can grow. The histidine auxotroph has a mutation in a gene (e.g. HIS3) of the histidine synthesis pathway and this mutant strain will grow in this medium if histidine is supplied from outside e.g. from a plasmid which contains HIS3 gene (3). For this purpose, a his3 mutant strain of S. cerevisiae is transformed with a HIS3 containing plasmid and the transformants can be selected by growing the cells on SD Growth Media w/o HIS. Hence this medium is very useful in molecular genetics.