Fig 2. Critical factors for co-transformation cloning.

A and B) E. coli cells were co-transformed with the lacZ insert PCR fragment and either PCR-linearized plasmid or restriction-enzyme digested/linearized plasmid. A) Data points represent the percentage of positive (blue) colonies averaged over three experiments ±SD. B) Data points represent the number of positive (blue) colonies averaged over three experiments ±SD. C and D) E. coli cells were co-transformed with the lacZ insert PCR fragment and PCR-linearized plasmid. The same experiment was also performed in the presence of a 10-fold molar excess over insert of each of two 15 nt long oligonucleotides comprising the sequence of the primer homology overhangs. All experiments were performed with and without a heat-denaturation / slow cooling step. C) Data points represent the percentage of positive (blue) colonies averaged over three experiments ±SD. D) Data points represent the number of positive (blue) colonies averaged over three experiments ±SD.