Molecular biology protocol: cytoplasm-nucleus separation

Cytoplasm-nucleus separation buffer (Buffer A)
 10mM HEPES pH7.9-8.0
 10mM KCl
 1.5mM MgCl2
 250-340mM Sucrose
 10% Glycerol
 1mM DTT
 Halt Protease inhibitor Cocktail (Thermo Scientific Cat#87786)

Method
1. Cells pellet down (5-10x10^6)
2. Add 150-200ul of buffer A with 0.1% TritonX100
3. Incubate on ice for 10-20min
4. Centrifuge 1000g 3min at 4°C
5. Collect the supernatant (cytoplasm fraction)
6. Wash the pellet twice with 800ul of Buffer A
7. Discard the supernatant (the pellet is nucleus fraction)