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.