Guanidinium thiocyanate—CsCl method

100 mM EDTA, pH 7.4 filtered and autoclaved Guanidinium thiocyanate lysis solution Dissolve 250 g guanidinium thiocyanate (Fluka) in 21 ml 1 M Tris-HCl, pH 7.6, 8.5 ml 10 mM EDTA and 150 ml H20 by stirring for 3-4 h. The solution is then filtered and 21 ml 2-mercaptoethanol (Merck) is added. Finally, pH is adjusted to 7.0 with NaOH and the volume is made up to 420 ml. 

Ultra-Clear tubes (14 x 89 mm, Beckman) Ultracentrifuge and SW41 rotor 

Adherent cells (about 108) can be lysed directly in the culture flasks whereas cells in suspension culture must be pelletted. Fresh tissue (about 1 g) should be cut into small pieces, and frozen tissue and material of plant origin ought to be crushed under liquid nitrogen.3 

Transfer the sample to a 50 ml polypropylene tube and add 7.5 ml guanidinium thiocyanate lysis solution. 

35 g sodium N-lauroylsarcosinate. Cap and invert the tube a few times—leave for 5-10 min. 

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