See the accompanying videos: http://www.youtube.com/watch?v=4ij8pYNFnEM http://www.youtube.com/watch?v=HgUgAeAb4Ng

1. Extracting DNA At Home
The Tech Museum of Innovation
San Jose, CA

2. What does DNA look like?

3. DNA is a double helix

4. What is DNA?

5. Genes are like recipes

6. Every living thing has DNA

7. Every living thing has DNA

8. Every living thing has DNA

9. An animal cell

10. An animal cell
Cell membrane

11. An animal cell
Cell membrane
Mitochondria

12. An animal cell
Nucleus Cell membrane
Mitochondria

13. DNA is kept inside the nucleus
Nucleus

14. To get the DNA out…

15. To get the DNA out…

16. Let’s get started!

17. Stuff you need
• Something with DNA

18. Stuff you need
• Strawberries

19. Stuff you need
• Strawberries
• Sandwich baggie

20. Stuff you need
• Strawberries
• Sandwich baggie
• Water

21. Stuff you need
• Strawberries
• Sandwich baggie
• Water
• Clear glass (or test tube)

22. Stuff you need
• Strawberries
• Sandwich baggie
• Water
• Clear glass (or test tube)
• 1/4 teaspoon measuring spoon
(optional)

23. Stuff you need
• Strawberries
• Sandwich baggie
• Water
• Clear glass (or test tube)
• 1/4 tsp measuring spoon (optional)
• Dishwashing soap

24. Stuff you need
• Strawberries
• Sandwich baggie
• Water
• Clear glass (or test tube)
• 1/4 tsp measuring spoon (optional)
• Dishwashing soap
• Rubbing alcohol

25. Step 1
Put the rubbing alcohol in the freezer

26. Plant cells are like animal cells
cell wall
Animal Cell
Nucleus (like our cells)
(with DNA!)
cell membrane
Plant Cell
(like a strawberry cell) mitochondria

27. Remember, to get the DNA out…

28. Step 2
Put 2 or 3 (or 4) strawberries in
the sandwich baggie

29. Step 3
Add a little bit of water
(to make it easier to pour out later)

30. Step 4
Seal the baggie

31. Step 5
Smush the strawberries!

32. Break down those cell walls!

33. Step 5
Smush for about 2 minutes or so…
Until there are no big chunks left and the
water is very red

34. Step 6
Pour the strawberry cell goo
into the glass

35. To avoid the chunks…
• Coffee filter
• Cheesecloth
• Or just pour carefully!

36. What’s in the glass?

37. See anything that looks like
DNA yet?

38. What’s in the glass?
Strawberry guts - yum!

39. What we just did

40. The DNA is still
inside the nucleus
Nucleus

41. Let’s break down
the nucleus wall!
Nucleus

42. How can we break the
nucleus wall?

43. The nucleus wall is
made of lipids (fat!)
Lipids = fat

44. Soap breaks apart grease & fat

45. Soap breaks apart grease & fat
And nuclear membranes!

46. Step 7
Add dishwashing soap
to the strawberry cell gut soup

47. See anything that looks like
DNA now?

48. Why can’t we see the DNA yet?

49. Why can’t we see the DNA yet?
DNA can dissolve in
the strawberry gut soup

50. Why can’t we see the DNA yet?
DNA can dissolve in Su gar
the strawberry gut soup
Like sugar
dissolves in water

51. But DNA does NOT
dissolve in alcohol!

52. DNA does NOT
dissolve in alcohol
When we add the alcohol, the DNA will
clump up so we can see it!

53. Step 8
Slowly add the cold rubbing alcohol to
the soapy strawberry goo

54. Make two separate layers
Like oil on water

55. What do you see?

56. Do you see some cobwebby
white stuff?

57. That’s the strawberries’ DNA!

58. That has all the instructions for
making an entire strawberry plant!

59. If you don’t see a lot of DNA…
• Keep watching!
• Or put your experiment in the fridge and
come back to look later
• Or do some experiments to see if you
can get more by trying out these next
things….

60. Things to experiment with…
• Amount of soap
• Different types of soap (brand, hand
soap, shampoo, laundry detergent, etc.)
• Number/size of strawberries
• Other sources of DNA (bananas, kiwis,
sweetbreads, peas, etc.)