FIGURE 5.

Caging of the cleavage site-surrounding nucleobases apparently inhibits the cleavage step of RNAi. (A) Fluorescence intensity of samples caged at positions other than those surrounding the cleavage site. HeLa cells were transfected with numerous siRNAs bearing one or two caging groups at positions either within the sense strand or not within the central cleavage region of the antisense strand. None of these sequences displays an inactivation close to that of the earlier tested sequences with cages within the cleavage region.