1. Homogenize cells or tissues. Extract proteins.
2. Add to the protein fraction (homogenate or pellet) a large volume of
acetone. Stirring for 30 minutes at room temperature.
3. Let the precipitate sediment or centrifuge to pellet.
4. Remove supernatant.
5. (optional) Wash the precipitate 3 times with 0.1 M NaCl. Each
time add large amount of 0.1 M NaCl, let the precipitate sediment or centrifuge to pellet, and remove the supernatant.
6. Add acetone, and filter through a funnel with a circular Whitman 3MM filter paper inside.
7. Wash several times with acetone.
8. Dry the precipitate on the filter paper at 37 °C.
9. If necessary, crush the precipitate into a fine powder in a small mortar and pestle.
10. If there is too much fat in the precipitate, wash the powder with chloroform twice and dry again.
11. Store desiccated at -20 °C.