Yeast DNA isolation with Lyticase or Zymolyase - MetabolicEngineeringGroupCBMA/MetabolicEngineeringGroupCBMA.github.io GitHub Wiki
This protocol does not include glass beads, so it should yield higher molecular weight DNA fragments. This protocol is based on Philippsen, P., Stotz, A., & Scherf, C. (1991). DNA of Saccharomyces cerevisiae. Methods in Enzymology, 194, 169–182.
- Grow cells in 15 mL of YPD overnight at 30 ºC (final O.D. should be greater than 3)
- Centrifuge cells at 5000 rpm for 5 min at 4 ºC. Discard supernatant.
- Resuspend cells in 1 mL of sorbitol 0.9 M EDTA.Na2 (pH 7.5) 0.1M -> Transfer to eppendorf
- Add 10 mL of lyticase (4 U/µL) and incubate for 1h at 37 ºC (or zymolyase 60 U/mL)
- Centrifuge cells (spheroplasts/protoplasts) at 5000 rpm for 5 min. Discard supernatant.
- Resuspend spheroplasts in 1 mL TrisHCl (pH 7.4) 50 mM, EDTA.Na2
- Add 30 µL of SDS 10% and mix thoroughly.
- Incubate at 65 ºC during 30 min.
- Add 250 µL potassium acetate 5M and incubate on ice for 1h (or at -20 ºC)
- Centrifuge at 10000 rpm for 10 min.
- Transfer supernatant to 2 new tubes and add 1 volume (750mL) of cold isopropanol (or cold EtOH). Mix thoroughly by inverting the tube and centrifuge at 5000 rpm for 15 min.
- Discard supernatant and incubate in 1 mL 70% ethanol for 5 min -> wash twice
- Let pellet dry and resuspend in 200 µL of TE (pH 7.4) - this might take some hours, therefore, incubate 10 min at 42 ºC in order to help speed it up
- Add 0.5 µL RNAse (1 mg/mL) and incubate for 30 min at 37 ºC
- Centrifuge for 15 min at 10000 rpm. Transfer supernatant to new tubes.