Purification of SR proteins from nuclear extract

20-30 ml frozen nuclear extract from approximately 1-5 x 10g cells or 10-20 1 HeLa cells (Section 3.1.1). 

SW28 rotor and Ultra-Clear centrifuge tubes (Beckman) 

Thaw nuclear extract (20-30 ml) (see Section 3.1.1) and dialyse for 3 h against isolation buffer. 

Transfer to four chilled 50 ml polypropylene centrifuge tubes and centrifuge at 8000 g for 20 min at 4°C. 

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