Figure 2.
Effect of alkaline phosphatase on the cleavage of SV40 L mRNA. HeLa nuclear extract was incubated with calf intestinal alkaline phosphatase, as in Figure 1. The samples were then assayed for cleavage in the presence of 3′ dATP and Mg2+ and varying amounts of alkaline phosphatase. Lanes 1–7 correspond to 0.01, 0.015, 0.02, 0.03, 0.04, 0.06, and 0.08 U/μg of alkaline phosphatase, respectively. Control samples consisted of incubation of the samples under the following conditions: lane 8, incubation for 30 minutes at 30°; lane 9, l0mM Hepes pH 7.6 in a volume to match that of the 0.08 U/μg; lane 10, 0.08 U/μg of alkaline phosphatase that was previously boiled for 5′; lane 11, a sample processed under normal conditions Without alkaline phosphatase.