Unit 3 – Lab 3.03/3.04 – Investigating Biological Compounds
The “Investigating Biological Compounds” lab is our next lab and the first lab in the Trace Evidence Units. Overall, you are working as a forensic chemist with the DEA to try to determine the organization that was the source for a substantial amount of cocaine that was found in a hotel in Oceanside, CA. You know there are three major organizations in the area that supply cocaine, and you know that each organization cuts their cocaine with a different type of white powder – powdered milk, cornstarch, and ascorbyl palmitate. You will learn about and use different testing reagents (stains) to identify the white powder that has been mixed in with the cocaine found in Oceanside.
In order to conduct this lab, you will need to print out the lab instructions and student guide. As you read through the background information (in 3.03), make sure to take notes on the reagents/stains you will use, including information on what each stain can be used to test for, how the stain works, and what the expected results are for a positive analysis. When you start the virtual lab in a separate browser window, you will first go to the tutorial and this will actually lead you into the analysis. When the tutorial ends, simply continue to follow the directions on the lab instructions (which you printed). Make sure to record your observations as you work through the tests. While it is not indicated, in the directions, you may use a stirring rod to stir your samples, and this may be particularly helpful with the Sudan III test. Once you have completed the tests listed in the directions, you will need to use the test tubes on the far right to test milk with all three stain solutions. Simply put milk in each of the three test-tubes, and then add the appropriate stain solution(s) and record the results. There is a quiz question about how milk responds to the stains, so please make sure you complete this additional test! In looking at all the solutions provided, you will not use the solution labeled ‘albumin’..
Virtual Lab . YOU NEED TO WORK THIS VIRTUAL LAB TO BE ABLE TO ANSWER THE QUESTIONS