Figure 1

Schematic illustration of the multiple patch cloning procedure. DNA fragments are amplified by polymerase chain reaction using two sets of oligo-DNA primers (shown in red and blue). The star on the primer indicates the site of mismatch. The resultant DNA fragments and digested vector DNA containing 16 bp homologous regions (shown in yellow) were assembled at 37°C by T5 exonuclease, Klenow fragment and T4 DNA ligase.