Figure 5

Incorporation of double and single BrdU residues by Bst exo^- DNA Polymerase into the 466 bp hybrid molecule. Incorporation reactions using BrdUTP alone or in combination with dTTP were carried out with Bst exo^- DNA Polymerase. Lanes M, Perfect 100 bp Ladder (selected bands marked). Enzyme purity and reaction steps controls: lane 1, uncut 437 bp PCR fragment amplified from pGCN1 plasmid; lane 2, uncut 480 bp PCR fragment amplified from pGCN2 plasmid; lane 3, BsaI-cut 437 bp fragment; lane 4, BsaI-cut 480 bp fragment; lane 5, BsaI restriction fragment I (191 bp) filled in with BrdUTP isolated from agarose gel; lane 6, BsaI restriction fragment III (270 bp) filled in with BrdUTP isolated from agarose gel; lane 7, BsaI-cut 437 bp fragment, purified and back-ligated; lane 8, BsaI-cut 437 bp fragment, purified, incubated with Bst exo- DNA Pol without dNTPs and back-ligated. Incorporation reaction: lane 9, fragment I (191 bp) filled in with dTTP, ligated to BrdU-labeled fragment III (270 bp); lane 10, fragment I (191 bp) filled in with BrdUTP, ligated to BrdU-labeled fragment III (270 bp). ^{I, III} BsaI restriction fragments numbered as in Figure 1.