Synthetic Complete Supplement Mixture w/o URA is used as a dropout supplement for all strains of Saccharomyces cerevisiae. It is composed of all the amino acids except uracil, uracil, the pyrimidine derivative. It can be mixed with yeast nitrogen base (YNB), ammonium sulphate and an appropriate carbon source (glucose/galactose/raffinose) to produce a media suitable for the growth of uracil prototrophs but not uracil auxotrophs