YEAST MEDIA PREPARATIONS
YPD
Bacto-yeast extract - 10 gm
Bacto-peptone - 20 gm
Bacto-agar - 25 gm
Add enough water to bring the volume upto 900 mL.
Autoclave for 20 min.
Add 100 mL 20% filtered dextrose and mix.
Pour plates.
Note:- For YPD media, do not add the bacto-agar.
2) SD medium:-
Bacto-yeast nitrogen base - 1.7 gm
(w/o amino acids & ammonium sulfate)
Ammonium sulfate - 5 gm
Bacto-agar - 25 gm
Add enough water to bring the volume upto 800 mL.
Autoclave for 20 min.
Add the following:-
Filtered 20% Dextrose - 100 mL
10x Amino acid mix - 100 mL.
NOTE:- For gal/raf medium, add 100 mL 0f 10x gal/raf i.e. 20% galactose (Sigma G-250) + 10% raffinose (Sigma R-750).
10x AMINO ACID MIX (L-Amino acids):-
To 800 mL of dH2O, add the following:-
Ade - 0.3 g Lys - 0.5 g Leu - 0.5 g Pro - 0.3 g
Ura - 0.3 g His - 0.3 g Phe - 0.6 g Ser - 4.0 g
Tyr - 0.6 g Met - 0.3 g Asp - 1.2 g Val - 1.5 g
Trp - 0.3 g Arg - 0.3 g Thr - 2.0 g Ile - 0.3 g
Glu - 1.0 g
Yeast Transformation
For a standard yeast transformation, miniprep DNA purified on columns or extracted with phenol/chloroform can be used. For 10 -15 independent transformations, a 100 mL culture is enough.
Inoculate yeast strain into 5 mL YPD. Grow at 30o C with vigorous shaking (250 rpm) O/N.
Add to 100 mL prewarmed YPD medium such that the OD600 is about 0.1 - 0.2. Grow at 30 oC with vigorous shaking till the OD600 reaches 0.5
Transfer to 2 50 mL tubes and spin at 3K for 5 min. at room temperature.
Discard the supernatant and resuspend the pellet in 5 mL TE/Li. Pool the pellets and spin in a 15 mL tube at 3K for 5 min.
Discard the supernatant and resuspend the pellet in 5 mL TE/Li. Incubate at 30oC for 30 min. with slow shaking.
Spin for 3 min. at 3K, discard the supernatant and resuspend the pellet in 1 mL. TE/Li.
Aliquot 100 ul. cells into each eppendorf tube and add 1-2 ug. of plasmid DNA to it. Also add ss carrier DNA to every sample.