A series of yeast shuttle vectors and host strains has been created to allow more efficient manipulation of DNA in Saccharomyces cerevisiae. Transplacement vectors were constructed and used to derive yeast strains containing nonreverting his3, trp1, leu2 and ura3 mutations. A set of YCp and YIp vectors (pRS series) was then made based on the backbone of the multipurpose plasmid pBLUESCRIPT. These pRS vectors are all uniform in structure and differ only in the yeast selectable marker gene used (HIS3, TRP1, LEU2 and URA3). They possess all of the attributes of pBLUESCRIPT and several yeast-specific features as well. Using a pRS vector, one can perform most standard DNA manipulations in the same plasmid that is introduced into yeast.