High-Frequency Lithium Acetate Transformation of Schizosaccharomyces pombe.

The introduction of ectopic DNA, such as plasmids, into yeast cells has for decades been a critical protocol for the study of this eukaryotic model system. We describe here an efficient transformation procedure for use in the fission yeast Schizosaccharomyces pombe. This method relies on chemical agents (lithium acetate, and polyethylene glycol) and temperature stresses, which ultimately facilitate transfer of the genetic material through the cell wall and plasma membrane without significant impact on the transferred DNA or the recipient cell. Using this protocol, we consistently see transformation efficiencies between 1.0 × 103 and 1.0 × 104 transformants per microgram of the plasmid with 108 S. pombe cells. The principal benefits and advantages of this method are its simplicity, efficiency, and relative speed of completion.