Technical Data
Yeast Nitrogen Base w/o AA, Carbohydrate & w/AS (YNB) (Powder)
Molecular Biology Grade
Storage RT/4°C    Shipping RT
Components per liter:
Ammonium Sulfate5g
D-Pantothenic Acid•Ca400ug
Folic Acid2ug
p-Aminobenzoic Acid200ug
Pyridoxine HCl400ug
Thiamine HCl400ug
Boric Acid500ug
Copper Sulfate40ug
Potassium Iodide100ug
Ferric Chloride200ug
Manganese Sulfate400ug
Sodium Molybdate200ug
Zinc Sulfate400ug
Potassium Phosphate Mono1g
Magnesium Sulfate0.5g
Sodium Chloride0.1g
Calcium Chloride0.1g
Yeast Nitrogen Base (YNB) media have been prepared according the formulae of Wickerham (1943-51) and Burkholder (1943). YNB is a well defined composition of salts, vitamins, amino acids and a nitrogen source for a vigorous growth of Sacharomyces cerevisiae.

Yeast Nitrogen Base without amino acids (YNB w/o AA), Y2025, is used for selecting yeasts based on amino acid and carbohydrate requirements. In Y2025, Ammonium Sulfate is included as a readily available nitrogen source for nitrogen assimilation. The medium includes all other vitamins, mineral salts and trace elements required for a vigorous growth of yeast cells. Compared to full YNB medium, Y2025 lacks Histidine, Methionine and Trypthophan. In combination with “Drop Out” medium supplement mixtures, Y2025 provides an excellent medium to cultivate and select auxothophic strains of yeast that requires the addition of essential nutrients like amino acids and/or vitamins.

For carbon assimilation tests in the characterization and identification of yeasts.

Note: The addition of a carbon source like glucose, galactose or raffinose is required.

Directions per Liter: Dissolve 6.706g in 800-900ml of ddH2O stirring gently until completely solubilized. Adjust pH of the medium to the desired level. Add additional water to bring the solution to1L Filter-sterilize using a 0.22 micron membrane filter. Aliquot into sterile containers. Do not autoclave. Contains heat-labile compounds that can be damaged with autoclaving.

Storage and Stability: Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.

Appearance: White to off-white, homogeneous, free-flowing powder

Solubility: Colorless to pale yellow, clear, complete

pH: 4.5±1.0

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.

1. Falcon-Perez, J.M. et al., (1999) J. Biol. Chem. 274:23584-23590. 2. Shell, S.S. et al., (2007) PNAS 104:10956-10961. 3. Reiner, S. et al. (2006) Mol Biol Cell 17:90-103. 4. Cronwright, G.R. et al., (2002) Appl. & Env. Microbiology 68:4448-4456. 1. Difco Manual Tenth Edition, pp.1136-1141(1984). 2. Ronald, M.: Atlas, Handbook of Microbiological Media, Lawrence C. Parks, ed., CRC Press (1993).