Complete Supplement Mixture w/o LEU-TRP is used as a dropout supplement for all strains of Saccharomyces cerevisiae. It is composed of all the amino acids and uracil except leucine and tryptophan. 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 Leucine and trptophan prototrophs but not leucine and tryptophan auxotrophs