Yeast Drop Out Bulletin

Yeast Synthetic Drop-out Media Supplements

Catalog Number Y1501: without uracil
Catalog Number Y1751: without histidine
Catalog Number Y1896: without lysine
Catalog Number Y1376: without leucine
Catalog Number Y1876: without tryptophan
Catalog Number Y0750: without leucine and tryptophan
Catalog Number Y1771: without uracil, leucine and tryptophan
Catalog Number Y2146: without histidine, leucine, and tryptophan
Catalog Number Y2021: without histidine, leucine, tryptophan and adenine
Catalog Number Y2001: without histidine, leucine, tryptophan and uracil

Note: Store at Room Temperature

Product Description

The selection of plasmids in yeast is based on the use of auxotrophic mutant strains, which cannot grow without a specific medium component (an amino acid, purine or pyrimidine). Transformation with a plasmid containing the mutated gene enables the transformant to grow on a medium lacking the required component. Although yeast can grow on a synthetic medium without any amino acids, better yield and growth rate can be achieved on richer media. Having a richer medium also increases the probability of successful transformations when screening libraries or performing gene knockouts. Composition of the media supplements are given in Table 1 and are based on published formulations.1

Precautions and Disclaimer

This product is for R&D use only, not for drug, household, or other uses. Please consult the Safety Data Sheet for information regarding hazards and safe handling practices.

Preparation Instructions

Yeast Synthetic Drop-out Medium Supplement                                             1.39–1.92 g/L
    (see Table 2 for appropriate amount for each supplement)

Yeast nitrogen base without amino acids                                                       6.7 g/L
    (Catalog Number: Y0626)

For plates add:
Bacteriological agar                                                                                     20 g/L
    (Catalog Number A5306)

When preparing plates, autoclave for 15 minutes only; autoclaving longer will cause agar to become soft. Alternatively, the agar can be autoclaved separately from the Synthetic Drop-out Medium Supplement and yeast nitrogen base.

After autoclaving add:

Glucose, 50% (w/v) solution                                                                         40 mL/L
(prepared from Catalog Number G7021, sterilized by 0.2 mm filtration)


Store media supplements desiccated at room temperature.

Table 1

  Component Amount per litre of medium (mg)*
1 Adenine
2 p-Aminobenzoic acid 8
3 Leucine 380
4 Alanine 76
5 Arginine
6 Asparagine 76
7 Aspartic acid 76
8 Cysteine
9 Glutamic acid
10 Glutamine 76
11 Glycine 76
12 Histidine 76
13 myo-Inositol 76
14 Isoleucine 76
15 Lysine 76
16 Methionine 76
17 Phenylalanine 76
18 Proline 76
19 Serine 76
20 Threonine 76
21 Tryptophan 76
22 Tyrosine 76
23 Uracil 76
24 Valine 76


























* Excluding dropped-out components

Table 2

Yeast Synthetic Drop-out Medium Supplement Amount per Liter of Medium
Y1501: without uracil 1.92 g
Y1751: without histidine 1.92 g
Y1896: without lysine 1.92 g
Y1376: without leucine 1.62 g
Y1876: without tryptophan 1.92 g
Y0750: without leucine and tryptophan 1.54 g
Y1771: without uracil, leucine, and tryptophan 1.46 g
Y2146: without histidine, leucine, and tryptophan 1.46 g
Y2021: without histidine, leucine, tryptophan, and adenine 1.39 g
Y2001: without histidine, leucine, tryptophan, and uracil 1.39 g














Growth test results

Table showing growth test results




  1. Kaiser C., Michaelis, S., and Mitchel, A., Methods in Yeast Genetics, a Cold Spring Harbor Laboratory Manual (Cold Spring Harbor, NY: 1994).