DNA Extraction

1. DNA Extraction
http://www.slideshare.net/iqbal1313/dna-
extraction-25521910

2. MATERIALS
• Dried split peas
• Dishwashing detergent
• Isopropyl alcohol
• Meat tenderizer
• Small cup or beaker
• Spoon

3. Start with the peas

4. Blend the peas with water and a
little salt until you have “pea soup”

5. Why do we blend the peas?
• The blender separates the pea CELLS
from each other

6. Put the strained pea soup in a cup
Add a squirt of dishwashing
detergent

7. Let the mixture sit for 5
minutes

8. What does the detergent do?
• Each pea cell is
surrounded by a cell
membrane
• DNA is in the nucleus
of a cell, which is also
surrounded by a
membrane

9. The membranes must be
broken open in order to get the
DNA out of the cell

10. Detergent:
• Breaks apart membranes by attaching to the
lipids (fats) & proteins in the membranes

11. The cell and nuclear membranes have been
broken apart,
as well as all of the organelle membranes,
such as those around the mitochondria and
chloroplasts.
So what is left?
• Proteins
• Carbohydrates (sugars)
• DNA

12. Add a pinch of meat tenderizer to
the mixture

13. Why?
• Meat tenderizer is an ENZYME
– A protein that helps chemical reactions
happen more quickly
• The enzymes in meat tenderizer break
apart proteins

14. The DNA in the nucleus is
surrounded by proteins

15. The meat tenderizer cuts away
the proteins from the DNA

16. Stir very, very GENTLY!

17. Tilt your cup & slowly pour a layer
of alcohol on top of the pea soup
mixture
• DNA will float up into the alcohol from the
pea soup