Our assignment this week in Understanding Genomes: extract DNA from strawberries. The “common strawberry” is an octoploid, meaning each cell contains eight copies of each chromosome. This makes it a prime candidate for experimentation. Here's the step-by-step process:
Step 1: Gather the ingredients. They are:
- Strawberries
- 1/4 tsp table salt
- 1 tsp dish detergent
- Meat tenderizer
- Water
- Rubbing alcohol (91% isopropanol)
And other needed equipment, including:
- Jar
- Funnel
- Coffee filter
- Sandwich bag
- Wooden skewer
Step 2: Add the strawberries, detergent, salt and meat tenderizer in the sandwich bag and knead for about 5 minutes. This “buffer” opens the cells of the strawberries, releasing the DNA. Add a little water and mix when finished.
Step 3: Pour through coffee filter into a jar.
Step 4: Slowly pour chilled rubbing alcohol down the side of the jar so that it floats above the strawberry mixture. Since DNA is insoluble in alcohol, it begins to clump together.
Step 5: After a few minutes, collect the DNA with a skewer. Mine looked like snot!
