DNA Forensic Lab Report: Who Murdered Romeo and Juliet

Introduction: According to The United States Department of Justice, “DNA can be used to identify criminals with incredible accuracy when biological evidence exists.  By the same token, DNA can be used to clear suspects and exonerate persons mistakenly accused or convicted of crimes.” (ADVANCING JUSTICE THROUGH DNA TECHNOLOGY: USING DNA TO SOLVE CRIMES | AG | Department of Justice, Accessed 1/26/17). Based on information The United states Department of Justice provides, DNA evidence has been an effective tool when identifying guilty and unguilty suspects of a criminal action. This lab will be used to solve an artificially made murder scenario based off of the book The Tragedy of Romeo and Juliet, by William Shakespeare. In the scenario Romeo and Juliet are murdered and a list of suspects are collected. One of these people’s DNA will match up with the DNA provided by the murderer. A Gel Electrophoresis Chamber will be used to determine the murderer. Purpose: Who is the murderer of Romeo and Juliet? Hypothesis: If Friar Laurence killed Romeo and Juliet, then his DNA will match the DNA the murderer provided, because Friar Laurence wanted to end the squabble  between the Montagues  and Capulets by uniting them through the death of Romeo and Juliet. Materials: 50 ml 0.9 percent salt water 5 disposable plastic cups 5 large test tubes (15 ml with screw on caps) 25 mL liquid detergent 75 mL water 25 ml 95 percent ethanol, chilled on ice 5 small test tubes 0.25 mL methylene blue solution per DNA sample Pipette and disposable pipette tips 5g Baking soda Agar powder 200 mL Deionized water 5 drops glycerin (1 drop per) Stainless steel wire Wire cutters Scissors 45 volt power supply 2 alligator clip leads Flat piece of Styrofoam for the comb One plastic box, big enough to hold the gel 500 mL of deionized water 5g baking soda 5 grams agarose Separate container for mixing materials (a bowl is suggested) Butter Knife Suspect Travel Distance of DNA Bands (cm) Suspect #1: Friar Laurence Results Inconclusive Suspect #3: Montague Results Inconclusive Suspect #8: Benvolio Results Inconclusive Suspect #9: Paris Results Inconclusive Suspect #10: Capulet Results Inconclusive Procedure: Creating the Gel Electrophoresis Chamber: Cut two pieces of stainless steel wires that are roughly 1 inch longer than the longest length of the box. Bend the wires along the shortest width of the bin so that they touch the bottom. The excess wire should be hooked to the edge of the bin so it stays in place. Once the wires have been shaped, remove them from the box and keep them in a safe place. Create a comb using styrofoam. Make sure the top part of the comb is wide enough to rest on the edges of the plastic bin. The bristles should end at least 2 millimeters above the bottom of the plastic bin. Make one tooth for each suspect that is being tested. The distance between each tooth should be evenly spaced. Place the comb into one end of the plastic bin.         Collecting DNA Samples: Have each murder suspect swish 2 teaspoons (10 ml) 0.9 percent salt water in their mouth for 30 seconds. Spit the water into their cup. Each suspect should be using a different cup, no sharing! Make a 25% mild detergent solution by combining 5 ml of liquid detergent and 15 ml of water. There should be enough of the solution for each suspect. Take 5 ml of each DNA sample them in their own test tube. Label each test tube according to what DNA it contains Add 5 ml of the 25% mild detergent solution to each test tube. Cap each test tube and swish them on their sides for 2-3 minutes. Be careful when rocking the solutions so that the DNA does not forcefully break apart. Open the tube and add 5 ml of the chilled 95% ethanol to the tube. It will form a layer on the top of the DNA solution. Allow the tubes to stand for 1 minute. While the tubes are standing, label one micro test tube for each regular sized test tube. Use a syringe or eyedropper to take 0.25 ml DNA from the top of each test tube. Add each DNA to it’s own micro test tube. Make sure that a new eyedropper is used for each DNA sample. Use the disposable pipettes to add 0.25 ml methylene blue solution to each micro test tube. Add one drop of glycerin to the micro test tube with the DNA/methylene blue solution. Close the test tubes tightly until they are ready to be put in the gel electrophoresis box. Testing the Results:       Make a 1% solution of baking soda for the new buffer solution. Measure 2 grams of baking soda and add it to 200 mL of bottled water. Stir this mixture well. Make a 1% agarose solution. This can be accomplished by combining 1 g of agar powder with 100 ml of the buffer solution made in the previous step. Heat the agar solution on a hot plate or in a microwave. In the microwave stop the timer every 10-15 seconds to stir the solution. If it is heated on the hot plate make sure it is stirred often throughout the heating process. When the solution starts to bubble, take it off the hot plate or remove it from the microwave. The solution should appear translucent.      After the agarose solution is made, pour the it into the plastic bin. Carefully remove the comb from the solidified gel. The indents from the comb will be where the DNA is placed later. Use the butter knife to cut a thin slice of gel from both the top and bottom. These cuts will fit the wires Fit the stainless steel wire (electrodes) into the cuts made in the previous step. Use an eyedropper or syringe to fill each well in the gel with a different suspect’s DNA. Be sure to record what DNA solution is placed in which well. Pour the buffer solution over the gel once it has set. If necessary, make more buffer solution to cover all of the gel. Data Table: Identify the Independent and Dependent Variable: X: Suspects Y: DNA’s Distance Graph:        #1 Scatterplot (With fake data)     #2 (Should be) Scatterplot with actual data                                                                  Lab Results: Inconclusive Conclusion: The results derived from the lab itself were futile. There were many inconsistencies with the lab. The variable that made the results futile, however, were due to the wires not being stainless steel or galvanized. Rust collected in the gel scattered the liquid solution in different directions and prevented parts of the solution from becoming measureable. Chemical elements in the rust may have also altered the DNA solution. This variable didn’t allow our team to collect DNA evidence. Results from the curators of the lab revealed that Friar Laurence was the murderer. The hypothesis our team came up with was correct, because Friar Laurence was indeed the murderer of Romeo and Juliet. If the lab is attempted again it would necessary to advise the use of stainless steel or galvanized wire, so rust won’t ruin the Gel Electrophoresis Chamber . Editing should be done to the procedures of the lab to insure that it will succeed in a following attempt. In the future it would be interesting to find a way to create a more stable environment to test DNA in.