The RNzol LS procedure represents a well-established technology for RNA purification. This technology combines the selective binding properties of a silica-based membrane with the speed of microspin technology. A specialized high-salt buffer system allows up to 100 μg of RNA longer than 200bp binding to the RNzol LS silica membrane. Biological samples are first lysed and homogenized in the presence of a highly denaturing guanidine-thiocyanate–containing buffer, which immediately inactivates RNases to ensure purification of intact RNA. Ethanol is added to provide appropriate binding conditions, and the lysate transferred to the spin-column, where the total RNA binds to the membrane and contaminants are efficiently washed away. High-quality RNA is then eluted in 30-100 μl water.