David Higgins and James Cregg compile for the first time an all-inclusive collection of key experimental procedures to manipulate Pichia pastoris for gene expression purposes. The methods—developed by world-class researchers in their own laboratories—contain detailed descriptions of available expression strains, as well as vectors and step-by-step instructions for the construction of expression strains and for their use in the production of foreign proteins from shake-flask or fermentor cultures. General procedures for the purification of foreign proteins are also provided, along with protocols for analyzing foreign protein products for glycosylation and subcellular location. Its detailed instructions will permit any researcher in molecular biology to quickly construct an expression strain that will produce a desired foreign protein, and to use this state-of-the-art molecular and cellular biological system successfully in every area of biological research today.