This simple activity can make DNA a real and visual thing for students.
– Ziploc bag
– extraction buffer (90mL of water, 50mL of soap, 1.5g of salt)
– test tube
– cold ethanol
– stirring rod
1. Put a strawberry in the bag, and squash it up well
2. Add 10mL of extraction buffer, and mix well
3. Filter the solution into a test tube using cheesecloth and funnel
4. Gently add cold ethanol until the test tube is ~1/2 full
5. DNA should precipitate out in strands, and it can be caught on a stir rod
This is more for students to do themselves, as it would be hard to see one central demo of this.
Safety goggles should be worn at all times
Britos, L.; Goyenola, G.; Orono, S.U. Simple Protocol for Secondary School Hands-on Activity. Biochemistry and Molecular Biology Education. 2004, 32 (5), 341-347.