DNA Extraction Lab

DNA is a vital building block of all life. It is necessary for reproduction, and contains the genetic information that is passed on between generations. The lab that we are presented with today calls for us to extract the DNA from a strawberry fruit and report on each of the steps and tell why they are necessary.

  1. The first step was to create a DNA extraction buffer with our groups. This buffer consists of detergent, salt, and water as shown below. The detergent in the buffer is a strong ase and breaks down the membranes of the cells, dissolves the nuclear membrane, and releases DNA. The water provides a solute for the creation of a solution that dissolves the membranes and cytoplasm of the cells. The salt separates DNA from enzymes within the nuclear membrane of the cell and causes the DNa to clump together.

<The ingredients for the buffer before mixing. Salt, liquid detergent, and water.
















   2. Next we poured 10 mL of the solution into a tightly sealed ziploc bag along with the strawberry. Then we would massage the strawberry until it became a paste that was mixed in with the extraction buffer as shown in the picture below. By crushing the strawberry the cells break open allowing the ingredients of the buffer to break apart the membranes of the cells and nuclei.

3. The next step was to place a lining of gauze into a funnel, and to pour the mixture into the funnel as shown below. The gauze separates the DNA and extraction buffer from the solid strawberry debris.

4. Finally, we used our pipette to put a layer of ethanol on top of the strawberry DNA solution. The strawberry DNA cannot be dissolved by the alcohol ad since its density is very low it floats to the top of the solution. The light pink threadlike solution is the strawberry DNA that has floated to the top of the solution. The picture below shows the DNA that has risen into the clear ethanol above the strawberry and buffer solution.

What I learned from this lab is that the DNA in plants and animals can be extracted through relatively simple means. It helped me understand the structure of DNA. Most importantly, I learned that DNA is contained in all living things and is a necessity of life.