A simple and efficient procedure for transformation of Schizosaccharomyces pombe

We describe a simple and efficient procedure for transformation of Schizosaccharomyces pombe. Sz. pombe colonies grown on minimal (SD) plates were directly removed and suspended in a 100 microl reaction mixture containing 70 microl PLATE solution (50% polyethylene glycol-4000, 100 mM lithium acetate, 10 mM Tris-HCl, pH 4.9, and 1 mM EDTA), 10 microl plasmid DNA (1 microg), 10 microl carrier DNA (100 microg) and 10 microl sterile distilled water. After incubation at 30 degrees C for 1 h followed by heat shock treatment at 42 degrees C for 15 min, the reaction mixture was spread on a selection plate. The transformation efficiency obtained using the procedure was approximately 8000 transformants/microg DNA. The method is simple and time-saving, making it especially useful for a large number of samples and when a high transformation efficiency is not required.