Gel electroelution protocol.

Remove the two outermost lanes containing RNA ladders from the gel using a clean razor blade and glass slide ruler. This separation allows the ladder lanes to be stained without staining the RNA sample to be extracted in the middle lanes.

Add gel red stain to the separated outer lanes and incubate on a shaker for 30-45 minutes to visualize the RNA ladder bands. Keep the middle gel section in water to prevent drying and stain binding to the target RNA.

Reassemble the three gel pieces back together with the stained ladders visible on the edges. Use a UV lamp to visualize the stained ladders and identify the desired RNA band by size, then carefully cut out the target band using a clean scalpel blade.

Using a clean spatula, transfer the excised gel bands onto parafilm, then place each band into a cleaned and autoclaved dialysis tube. Fold and clip one end of each tube closed to seal it shut.

Use a micropipette to add running buffer to each dialysis tube, ensuring the gel band is completely covered but minimizing excess volume to reduce later concentration steps. Fold and clip the other end of each tube closed to seal it completely.

Place each sealed dialysis tube horizontally inside the gel electrophoresis tank, ensuring the gel bands are perpendicular to the voltage field. This orientation allows RNA to be electro-eluted directly out of the gel bands and into the running buffer.