To convert the host phenotype from HIS3 to LEU2, transform with the ApaI+PstI digested vector and select for Leu+ transformants.
Some combinations of marker swap plasmids and target locus may result in relatively high reversion rates. In most but not all cases the frequencies of successful convertants are greater than 30%.
A marker swap vector designed to change the S. cerevisiae host phenotype by one-step gene disruption of the HIS3 gene with a LEU2 marker.
When swapping markers on an episomal plasmid, appropriate phenotype may result from loss of the plasmid unless a second selectable or scorable marker is used to ensure plasmid maintenance.
Vector was constructed by replacing an internal BglII fragment of HIS3 with a 2.7 kb BglII fragment containing the LEU2 coding sequence. LEU2 and HIS3 are in the same orientation.
Media
ATCC® Medium 1675: LB medium (ATCC medium 1065) with 10 mcg/ml Chloramphenicol