Highly sensitive northern hybridization using a rapid protocol for downward alkaline blotting of RNA

A simple and fast RNA gel blot procedure is described that uses 50 mM NaOH to simultaneously transfer and fix RNA to a positively charged nylon membrane. The RNA is transferred in a downward direction, and transfer is routinely completed within 2.5 h. The resulting blots give increased sensitivity over existing methods without affecting RNA integrity and can be used in both radioactive and nonradioactive detection procedures.