YPD or YEDP (Yeast Extract Peptone Dextrose) medium

We sometimes use YPDlight instead of YPD. This medium is for general growth of yeast strains. See wikipedia article.

For liquid medium, add the following dry components in a 1L bottle:

• 20 g/L peptone or tryptone
• 10 g/L yeast extract
• 20 g/L glucose

Add a magnetic stirrer and fill up to the 1L mark on the bottle. Alternatively, from sterile stock solutions, 50 mL :

• 25 mL P40Y20
• 2 mL glucose (50%w/v; 20x)
• 23 mL dH2O

Mix in a sterile 50 mL Falcon tube in a Laminar flow cabinet or next to a bunsen burner.

Ordinary tap water can be used since tap water was used to produce the yeast extract and the peptone in the first place. There is normally no need to set the pH, it should be around 7.

Autoclave with a small piece (0.5 - 1 cm) autoclave tape on the lid.

This medium can also be prepared in dry form and then mixed with water and heated using a microwave oven: YPDpowder

For solid medium, add the following to a 1L Schott bottle:

• 10 g peptone or tryptone
• 5 g yeast extract
• 10 g glucose
• 10 g agar

Add a magnetic stirrer and fill up to the 500 mL mark on the bottle.

Mark the flask with AGAR with big letters on the side of the flask. Put the flask on the small trolly outside the autoclave room.

Dr. Luis will put the flask in the 50°C incubator to cool down after autoclaving.

Add water to 500 mL and a magnetic stirrer. Autoclave with lid loosely fitted. Do not make more than about 1/2 L in a one liter bottle since the medium otherwise can boil over.

Pour the plates after the medium has cooled down.

Reuse the plastic bag that the plates came from to store the plates.