Extraction of Total RNA from Tissues and Cultured Cells

The rsolatron of intact, high quality, total cellular RNA is often the starting point for many molecular biologrcal procedures (Fig. 1 ) There are numerous general methods for the rsolation of total cellular RNA (1 –9 ). There are also many specialrzed methods for the rsolatron of RNA from specific tissues (8 –10 ), various cell types (11 ), and subcellular organelles (7 ,12 ,13 ) In addmon, a number of methods describe the srmultaneous rsolatton of RNA and DNA (14 –17 ). Generally, the rationale for any tsolation procedure is to solubihze cellular components and simultaneously mactrvate mtracellular RNases while mamtaming brologrcally active RNA Therefore, the goal is to acquire purrfied cellular RNA in an intact form that can be a substrate for further mampulatrons, such as in vitro translation, RNase protectton, reverse transcrrptron, and Northern-blot analysis.