Pre IB Biology Lab #3: DNA Extraction

Prepared For: Courtney Oliver By: Adefemi Obisanya Date: December 21, 2012 In this lab, the researcher purpose for conducting this experiment is to become familiar with a procedure for extracting DNA, collect DNA samples and observe the physical characteristics of DNA. The hypothesis is that the DNA extracted from the strawberry will look like clump strands that cannot be seen by the naked eye. Materials
Zip lock sandwich bag
1 ripe strawberry
Lysis buffer
Coffee filter
Erlenmeyer flask
Graduated cylinder
Small funnel
Glass slide
Ethyl or isopropyl alcohol
Ice water bath
Test tube
Plastic stirrer
Scissors
Safety goggles
Procedure
1. Obtain 1 fresh strawberry. Remove any of the leaves if they are attached.
2. Place the strawberry in the zip lock bag. Squeeze all the air out and seal the bag tight.
3. Gently mash the strawberry in the bag with your fingers for at least 5 minutes. Do not break the bag
4. At the end of 5 minutes, add 10 m-ml of the lysis buffer to the bag. Squeeze the air out again and seal the bag tight.
5. Mash the bag with the lysis buffer for 2 minutes. CAUTION: Mash the mixture carefully; the fewer bubbles created the better the results.
6. Place the funnel in the flask and place the coffee filter in the funnel.
7. Cut one of the bottom corners of the baggie off and slowly squeeze the strawberry liquid and the pulp into the funnel.
8. Allow the liquid to flow into the flask. Do not force the liquid.
9. Pour the filtrate into a clean test tube making sure to leave room for the alcohol
10. Slowly pour ice cold alcohol down the side of the test tube so it forms a separate layer on top of the strawberry liquid. Do not pour the alcohol directly into the filtrate.
11. Wait about a minute and observe the formation of a thin cloudy layer in between the two liquids. This is DNA.
12. Take the plastic stirrer and gently dip the tip into the DNA fibers and slowly pull the fibers up and place a small sample on a clean glass slide

Of the data collected, it can be said that the DNA was shown and extracted in the experiment and the DNA looked like small microscopic bubbles and had a resemblance that reminded me of lint. After the mashing, the bubbles appear in multitudes, but subsided in later part.
Assigned Questions:
1. Define: Diploid, octoploidy and filtrate.
A. Diploid - A cell or an organism consisting of two sets of chromosomes: usually, one set from the mother and another set from the father. In a diploid state the haploid number is doubled, thus, this condition is also known as 2n.
B. Octoploidy - having a chromosome number eight times the basic haploid chromosome number.
C. Filtrate - To put or go through a filter
2. Describe the function of DNA molecule be found
DNA is the blueprint that allows a plant or animal to divide itself, from a single-cell, into an extremely complex organism with many different kinds of cells and containing many millions of cells. DNA also allows for both sexual and asexual reproduction, depending on the organism in question. It also takes noting that DNA is what is responsible for the variety of plants and animals that exist due to its central role in evolution. Small mutations of DNA information, over long periods of time, lead to