Enhancing Yeast Transformation: Achieving up to a Tenfold Increase Through a Single Adjustment in the Lithium Acetate–Polyethylene Glycol Method

Abstract

The Lithium–PEG method for transforming yeast cells is a standard procedure used in most yeast laboratories. After several optimizations, this method can yield up to 106 transformants per µg of plasmid. Some applications, such as library screening or complex transformations, necessitate maximizing transformation yield. Here, we demonstrate that the addition of a sorbitol solution serves as an osmo-protectant during and after heat shock, resulting in up to a tenfold increase in transformation efficiency. This optimization requires only one additional pipetting step compared to the original protocol, making it practical for routine use.