Smolke:Protocols/Dropout plates
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Overview
Making selective yeast plates.
Materials
- Nanopure water
- Yeast nitrogen base (YNB)
- Ammonium sulfate
- Agar
- Sugars (normally 20% dextrose, alternative 20% raffinose/10% sucrose/20% galactose)
- Amino acid dropout solution (in 4°C room)
Procedure
N.B. - this protocol makes 12 plates. Adjust volumes as needed.
- Mix:
- 200 mL NP water (or less, if using alternate sugars)
- 0.425g YNB
- 1.25g NH4SO4
- 5g Difco agar (not Bacto agar)
- Mix the solution well and autoclave on liquid cycle
- After autoclaving, run cold water over the bottle to cool
- When bottle is cool enough to touch with the bare hand, add dropout solution and sugar(s)
- Swirl to mix, then pour into plates
- Pour just enough cover the base (shake the plate a little to get an even layer)
- Briefly flame the top of the plate to eliminate bubbles
Notes
- Before autoclaving, the mixture will separate into two layers. It should go into solution after autoclaving.
- If pouring multiple bottles of media, the remaining bottles can stay in the autoclave until needed.
- I've found that it cuts down on condensation if you pile the plates on top of each other while they dry. -Jkm