Northern Blotting 1. Photograph gel with ruler along left-hand side. 2. Cut off markers and bottom left-hand corner of gel. 3. Place gel in tray and add tepid DEPC-treated water to cover gel. 4. Gently shake for 15 min. 5. Set up tray with perspex sheet on top and make a wick with 3MM paper. 6. Into tray place 20X SSPE to form a reservoir of buffer. 7. Measure gel and cut 10 pieces of 3MM paper to gel size. 8. Carefully cut Hybond N (between protective sheets) to gel size. 9. Remove water from tray and carefully invert gel and place on wick. 10. Seal around the edges of the gel with either used X-ray film or Saran wrap, to avoid any short-circuiting of the blot. 11. Cover the remainder of the reservoir with Saran wrap to avoid loss due to evaporation. 12. Mark the Hybond N with the date and your initials (in pencil) and carefully place (writing side facing gel) on top of the gel. 13.Wet 5 pieces of the cut 3MM paper with 20X SSPE and place on top of the membrane. 14.Add the remaining 5 pieces of dry 3MM on top. 15. Stack brown towels on top of the 3MM paper to a height of approximately 3cm. 16. Place a perspex sheet on top of the towels and a weight, approximately 500g. 17. Blot overnight. 18. The following day, dismantle the blot, place the filter RNA-side up on a paper towel and allow to air-dry for 1 hour. 19. Discard the gel in the biohazard bag. 20. After 1 hour wrap the filter in Saran wrap and UV-crosslink on the UV transilluminator for 6 min (RNA-side down). 21. Store filter safely until required.