cell fractionation

1) cut tissue

• cold to slow reactions
• isotonic to stop osmosis
• buffer to stop ph changes

2) grind tissue

3) filter to remove insoluble tissue

4) centrifugue

• low speed - nuclei
• medium speed - mitochondria / chloroplasts
• high speed - er / golgi
• very high speed - ribosomes

5) organelle free cytoplasm is left over