Aim: How can we extract the DNA from a strawberry? Do Now: 1) What is the building block of protein? 2) What is the basic unit of DNA? 3) What is the building block of living things? 4) What is the subunit of protein? 5) What is the subunit of DNA?

Pre-Lab Questions Where in the cell is DNA found? What structures will we have to break through to reach the DNA? What would you expect the DNA to look like?

Strawberry Cell

When the strawberry is crushed, enzymes break down the cell wall.

When the extraction buffer is added, the organelles and nuclear membrane are broken apart.

Strawberry DNA In-Class Lab 1) Place one strawberry in a Ziploc bag 2) Smash/grind up the strawberry using your fist and fingers for 2 minutes. Be careful NOT to break the bag.

When the strawberry is crushed, enzymes break down the cell wall.

Strawberry DNA In-Class Lab 3) Add10 mL of the extraction buffer (salt and soap solution) to the bag. 4) Kneed/mush the strawberry in the bag again for 1 minute.

When the extraction buffer is added, the organelles and nuclear membrane are broken apart.

Strawberry DNA In-Class Lab 5) Pour the strawberry slurry into the coffee filter and let it drip directly into your beaker. You can gently squeeze the filter to get the liquid out. 6) Slowly pour cold ethanol into the tube. 7) Dip the popsicle stick into the mixture. Lift the DNA out onto the popsicle stick.

When the ethanol is added, the DNA will clump up in it and can be easily lifted out.

Complete the questions on your lab sheet.

Summary Questions 1) Restriction enzymes are a substance that breaks apart DNA. If we added restriction enzymes to our result, how do you think it would change? 2) Did the DNA you saw reflect your prediction in the pre-lab question?  How can you explain the reason it looked the way it did?