YNB media, Yeast Nitrogen Base, without Amino Acids | 250g

YNB without Amino Acids

250g, fine powder, up to make 18.6L liquid media (for 10 X stock)

500g, fine powder, up to make 37L liquid media (for 10 X stock)

Yeast Nitrogen Base (YNB) is a basic medium for the preparation of minimal and synthetic defined yeast media. YNB contains ammonium sulphate but no amino acids.

YNB is a chemically defined, carbohydrate-free medium to which individual carbohydrates can be added. Ammonium sulphate provides a nitrogen source. The medium also contains essential vitamins, trace elements and salts. In addition, histidine, methionine and tryptophan (not included in YNB without AAs) can provide the necessary amino acids.

Applications

For Saccharomyces cerevisiae, Pichia pastoris culturing

YNB can be used for yeast identification by the assimilation test, which uses a chemically defined liquid broth medium containing a single sugar.

YNB is also recommended for use in antifungal susceptibility testing.

Components, mg per litre

Yeast Nitrogen Base (YNB), per litre

YNB stock Preparation

Preparation of 10 X stock (6.7% w/w for Saccharomyces cerevisiae, while 13.4% w/w for Pichia pastoris) yeast nitrogen base with ammonium sulphate without amino acids.

[Small scale preparation]

1.       Dissolve 67g/134g YNB with ammonium sulphate and without amino acids in 950ml of million-Q or distilled water, mix well and heat the solution to 45°C to dissolve the YNB completely and make up to 1000ml.

2.       Filter (0.22 µm) sterilise, seal the prepared stock within a GL45-cap reagent bottle and store at 4°C, the shelf life of this solution is approximately one year.

[Mini Preparation]

1.       Dissolve 6.7g | 13.4g YNB with ammonium sulphate and without amino acids in 95ml million-Q or distilled water, mix well and heat the solution to 45°C to dissolve the YNB completely and make up to 100ml.

2.       Sterilise the solution using a 0.22µm syringe filter and transfer the prepared stock into 50ml centrifuge tubes and store at 4°C.

Medium Preparation

Dissolve 1 volume of YNB 10X stock in 8~9 volumes of autoclaved million-Q water, with a suitable amount of sterilised Dextrose stock, and amino acids stock, make up to the final volume and use directly.

Minimal Dextrose Medium (MD media) for Saccharomyces cerevisiae

0.67% YNB

5% Dextrose (by adding 5X D stock | 25% D-glucose)

Minimal Dextrose Medium (MD media) for Pichia pastoris

1.34% YNB

0.00004% Biotin (by adding 500X B stock | 0.02% Biotin)

2% Dextrose (by adding 10X D stock | 20% D-glucose)

Minimal Methanol Medium（MM media) for Pichia pastoris

1.34% YNB

0.00004% Biotin (by adding 500X B stock | 0.02% Biotin)

0.5% Methanol (by adding 10X M stock | 5% Methanol)

Minimal Glycerol Medium（MG media) for Pichia pastoris

1.34% YNB

0.00004% Biotin (by adding 500X B stock | 0.02% Biotin)

1% Glycerol (by adding 10X GY stock | 10% Glycerol)

For plates

Add 15 g agar to 800 mL of MQ water and autoclave for 20 minutes on the liquid cycle. Cool till about 60°C, add sterile YNB/B/D/GY stock for a specific medium, make up to the final volume, and pour the plates immediately.

After opening and use, the remaining liquid should be sealed immediately and stored in the 4°C refrigerator. Operation on a sterile bench is recommended.