Yeast Cell Lysates

  1. Grow cells to 0.7 to 1.0 O.D.(600) (~1-2E7 cells/ml). Use about 2.0 to 4.0 OD of cells per lysate; if your cells are at 1.0 OD per ml, use 2 ml to give you 2.0 OD of cells in your lysate. Use 2.0 ml eppendorf tubes as the flat bottoms make glass bead lysis easier.

  2. Harvest cells by spinning in micro-centrifuge for 2 minutes, decant supernatant.

  3. Add 200 ul of SUMEB buffer + protease inhibitors.

  4. Add 100 ul of 0.5 mm Acid Washed Glass Beads.

  5. Vortex in multivortexer or by hand, 3 X 1 min speed setting 7 on our current machine (VWR multivortexer).

  6. Incubate for 10 min at 65oC or whatever temperature is desired.

  7. Remove the lysate from the beads with a blue pipette tip to a new 1.5 ml eppendorf tube.

  8. Spin 5 minutes to clarify. Remove supernatant to a new 1.5 ml eppendorf tube.

  9. Use supernatant directly to load gel or dot blot.
Note that protease inhibitors are added from stocks to give 50 fold dilution.
Example: 20 ul of stock per 1 ml buffer.

Use IMMEDIATELY after adding protease inhibitors.


SUMEB BUFFER
(1% SDS, 8 M Urea, 10 mM MOPS, pH 6.8, 10 mM EDTA, 0.01% bromophenol blue)

TO MAKE 100 ml:

  • 1.0 ml 1M MOPS, pH 6.8 stock solution
  • 1.0 g SDS, or 10 ml 10% SDS stock solution
  • 48.05 g Urea
  • 2.0 ml 0.5 M EDTA stock solution
  • 1.0 ml 1% bromophenol blue

This is used for lysing yeast at pH 6.8. For pH 8 lyses, use the variation of SUMEB with Tris buffer known as SUTEB.
Also, bromophenol blue can be left out if dye is not desired, such as using the lysate for immunopreicipations.

50X STOCK Protease Inhibitors (store at -20oC)

PMSF (87 mg/ml)
([500 mM] phenylmethylsulfonyl fluoride)

TO MAKE 30 ml:  Dissolve 2.61 g PMSF in DMSO to equal a final volume of 30 ml.

LEUPEPTIN AND PEPSTATIN (5 mg/ml)

TO MAKE 10 ml:  Dissolve 50 mg LEUPEPTIN or PEPSTATIN in DMSO to equal a final volume of 10 ml.

TPCK (5 mg/ml)
(tosylphenylalanine chloromethyl ketone)

TO MAKE 10 ml:  Dissolve 50 mg TPCK in DMSO to equal a final volume of 10 ml.


* Note: The EDTA in the SUME buffer is also a protease inhibitor.