pPIC9K vector carries the kanamycin resistance gene, resulting in Geneticin in Pichia pastoris ™ Reagent Resistance. The natural occurrence of multiple insertion events can be identified by the development of resistance to elevated levels of Geneticin™ reagent. Pichia pastoris transformants were selected on histidine-deficient medium and screened for resistance levels to Geneticin™ reagent. The ability to grow in high concentrations of Geneticin™ indicates that multiple copies of the kanamycin resistance gene and gene of interest have been integrated into the genome. The pPIC9K vector directs secretion of the expressed protein. This vector is included in the Multi-copy Pichia pastoris Expression Kit.