Mitotic stability assay

The mitotic stability assay was performed to determine the loss rate of pARS2, pmid8, pCEN8, pARS2-λ, pCEN801 and pCEN802 in C. tropicalis. Briefly, the C. tropicalis strain, CtKS102 transformed with above mentioned plasmids were streaked on CM-Ura plates for single colonies. Single colonies thus obtained were subsequently inoculated in a nonselective media (YPDU) and incubated at 30°C for overnight for at least 10 generations. Next day, equal numbers of cells were simultaneously plated on YPDU and CM-Ura and incubated at 30°C for 2 days. Colonies grown on both plates were counted and the mitotic stability was calculated in percentage as follows: Mitotic stability = (S/NS), where S and NS denote the number of colonies grown on selective and nonselective media respectively.