Alkaline phosphatase (AP) staining revealed that all colonies were pluripotent and the number of AP+ colonies were 51 at a multiplicity of infection (m.o.i.)of 0.4, 127 at 0.8 and 209 at 1.6, and the efficiency of reprogramming was 0.14% (Fig. 1B). Here, DHCR7-DT is linked to infection.