Rohini R Nair Answered May 19, 2022
Gujarat Biotechnology University
In brief, synthetic medium is prepared by mixing 7 g of synthetic dry mix (Dry mix is prepared by mixing 394 g Yeast nitrogen base with ammonium sulphate with 75 g Amino acid (0.3 g each of arginine, cysteine and proline; 0.45 g each of isoleucine, lysine and tyrosine; 0.75 g each of glutamic acid, phenylalanine and serine; 1.0 g each of aspartate, threonine and valine;) with 850 ml DDW, adding 350 ul of 10 N NaOH, followed by stirring and autoclaving in a large (i.e., 3 liters). Cool to room temperature before use. 100 ml of of 20% glucose (wt/vol) is added, as required, along with 10 ml of a sterile-filtered 100 aminoacid stock solution (see below).
The 100 amino-acid stock is composed of up to six amino acids/bases (e.g., adenine, histidine, leucine, methionine, tryptophan and uracil) for the preparation of specific selective media. For example, SC medium contains all six, whereas synthetic medium lacking uracil (SC-U) would contain all but uracil. The 100 amino-acid stock solution is prepared by first adding 0.4 g of each amino acid/base required to 150 ml DDW, followed by the addition of 3 ml concentrated HCl while stirring, developing the volume up to 200 ml, and then sterile filtering.