Cell FractionationCell Fractionation

The process by which cells are broken up and the organelles are isolated to be investigated.

Preparation

Homogenisation

StepStep ReasonReason

Ultracentrifugation

Make sure the 2 last boxes are larger than the others!

Step

Tissue placed in a…

1) Cold

2) Isotonic

3) Buffered

…solution

Reason

1)Prevent enzyme activity

2)Prevent osmosis

3) maintain correct and constant pH

Step

Tissue placed in a…

• Blender or pestle

• Fluid extracted (homogenate) and filtered

Reason

• Break cells up

• Remove whole cells and debris

Step

Homogenate placed into an ultracentrifuge

1. Spun at low speed (1000 x g)

2. Sediment in base, supernatant on top

3. Extract supernatant4. Spun at medium

speed (4000 x g)5. Extract supernatant6. Spun at high speed

(16000 x g)

Reason

1.Create a density gradient

2.Collect nuclei in sediment

3.Collect remaining organelles

4.Collect mitochondria in sediment

5.Collect remaining organelles

6.Collect E.R, lysosomes and ribosomes.

Bingo!Bingo!Draw a 3 x 3 grid and write in 9 of

the following words:

Lysosome, endoplasmic reticulum, mitochondria, golgi apparatus, ribosomes, enzymes, nuclei, isotonic, buffered, cold, homogenate, low speed, high speed, ultracentrifugation, cell fractionation,