NORTHERN BLOT AND HYBRIDIZATION Run a 1.5 - 1.8 % agarose formaldehyde gel. Blot directly into Nytran using 10 x SSC , overnight at room temperature. Remove membrane (trim if necessary) and put in a clean glass plate having the face in contact with the gel up. Cover with Saran Wrap and remove air bubbles that may be trapped. UV cross link. Remove membrane from plate and put in 1 x SSC - 0.1 % SDS at 50 o C for 45 minutes. To probe with random primed DNA Put membrane in HMA -50 5 x SSC 0.2% SDS, 0.02% BSA 0.02% Ficoll 0.02% PVP 0.5 mg / ml sonicated, denatured, Salmon sperm DNA 50 % formamide Keep solution at 4 o C Use to pre-hybridization and hybridization. 37 o C overnight. Washing: 0.1 x SSC , 0.1%SDS at 42 o C . 4 x 20 to 30 minutes each washing. To probe with oligomers Put membrane after UV and washing in : 6 x SSC 5 x Denhardts 0.5 mg / ml sonicated , denatured, Salmon sperm DNA 37 oC overnight Use to pre-hybridize and hybridize . Wash filters using the Tetramethylammonium chloride protocol (PNAS , 1985 vol. 82, 1585-1588)