(A) Sequence of Stem-s4U RNA. When this RNA is annealed, s4U is embedded in the stem structure. (B) Annealed and denatured Stem-s4U RNAs were spotted onto a nylon membrane filter and then visualized by methylene blue staining (upper). The chemiluminescence derived from the activity of HRP was monitored (middle and lower). To investigate the detection limit, exposure time was changed from 13 sec (middle) to 60 sec (lower). (C) Relationship between the amounts of RNAs and the chemiluminescence intensity of spots showed linearity. The chemiluminescence intensity of denatured Stem-s4U RNA samples is comparable with that of Linear-s4U RNA samples (Fig. 2D). Relative intensity is defined so that the chemiluminescence derived from the 50 pmol Stem-s4U sample is expressed as 1.00.
