SD Medium-LEU is a single dropout synthetic medium for selective growth of Saccharomyces cerevisiae.
- Molecular Biology Certified
- Used for confirming auxotrophic phenotypes
- Selects for yeast transformants
Reagents are tested and chosen for their ability to promote optimum growth of yeast strains when combined in the SD Medium-Leu formula. DOB (Drop Out Base) is 1.7g Yeast Nitrogen Base, 5g Ammonium Sulfate, 20g Dextrose per liter. DOBA is DOB with 17g per liter of agar. Chosen reagents are combined in the proper proportions according to the formulation listed in the certificate of analysis and milled to a powder which thoroughly blends the reagents for uniform distribution. A sample of the milled and blended formulation was used to prepare plate medium by adding 27.4g of SD Medium-Leu and 17g Agar to 1000mL of purified water. The combinations were mixed by hand for about 1 minute to dissolve the dextrose and autoclaved at 121°C for 15 minutes. After cooling to 50°C plates were poured. SD Medium-Leu (DOB with CSM-Leu) with agar was visually inspected after autoclaving for complete dissolution of components. The pH of the medium was tested to insure that the proper specification was attained. Acceptable pH range is 3.6 - 5.5 in DOB and 5.0 - 5.8 in DOBA. The SD Medium-Leu was tested by spotting 16 strains of yeast that have distinct auxotrophic phenotypes onto the plates and incubating at 30°C. On days 2, 3 and 4 plates were examined for the pattern of growth. All strains grew on SDA Medium (DOBA with CSM plates), i.e., with complete supplement mixture and no "drop-outs".