Figure 3.

Chain extension reactions catalyzed either by KF exo⁺ (0.02 or 0.2 U), KF exo^– (0.01 or 0.1 U) or RT (4 or 10 U). Reactions were carried out at 30°C for 30 min using the unmodified 34mer (sequence 2, 0.06 µM) or the modified 34mer L template (sequence 1, 0.06 µM) primed with the ³²P-labeled 18mer (sequence 3, 0.05 µM) in the presence of the four dNTPs (at a final concentration of 100 µM each).