Figure 5.

Cleavage levels (%) of siRNAs by RNAse A, as determined in autoradiographs ((A), two blocks) and fluorescent scanning gel images ((B), two blocks). The leftmost column in each block shows types of antisense chains; upper rows indicate types of sense chains. Each block contains data on the cleavage extent of a particular siRNA site. The blue arrow in the upper block of (A) means that this block shows the extent of cleavage of the U₁₈ site in the sense chains of the duplex. The black arrow in the bottom block of (A) means that this block presents the extent of cleavage of the C₄ site in an antisense strand. The double blue-and-black arrow in the upper block of (B) means that this block shows the extent of cleavage of the U₁₈ site in sense chains and of the C₄ site in antisense chains. The double red-and-green arrow in the bottom block of (B) means that this block shows the extent of cleavage of U₁₂ and C₁₆–U₁₇ sites in antisense chains. The most stable siRNAs are boxed (violet frames). The extent of the degradation was calculated as the ratio of the intensity of a given band to the total intensity of all bands in a lane, multiplied by 100%. A lower value means lower degradation. Relative error in all the experiments did not exceed 20%. The asterisk (*) means the PG-modified chain. The data are presented as mean ± standard deviation from at least three independent experiments.