Figure 2. Snail organs transfected with or without the fluorecent siRNA visualized by either light or fluorescence microscopy.

Panels A and C: Images of snail hepatopancreas and ovotestis tissues of juvenile snails that were either soaked in fluorescent siRNA (A) for 72 hrs or left untreated (C) viewed without fluorescence (10× magnification). Panels B and D: The same images of hepatopancreas and ovotestis regions shown in panels A and C, subjected to fluorescence microscopy as described in Materials and Methods. Note the very weak flourescence (red stain) in the hepatopancreas (B) indicating less uptake of the fluorescent siRNA into this tissue occurs without PEI (10× magnification).