You will be conducting a bioassay to determine the toxicity of a chemical. Read the Protocols 1 and 2 (see readings in "Schedule" Angel page). In class, you will be setting up the bioassay with a chemical of your choice. We will have a few suggested chemicals on hand, you may select one from the SCIED chemical stores, or you may use an environmental sample of your choice.
1. If you have not already done so, register on the EI web site, by surfing to http://ei.ed.psu.edu/CPR/ and then clicking on "Step 1 -- Register." The registration process includes a consent form where you indicate whether or not you wish to participate in an evaluation of the project, by completing an online questionnaire about your experience after your experiment is concluded. Completion of the questionnaires is completely optional and will have no effect on your grade.
2. Next, select your chemical. If you use one of the "suggested" chemicals, review the Material Safety Data Sheet (MSDS) for that chemical (it is in a 3-ring binder). If you prefer to use a chemical from the storage room, you will first need to locate the MSDS, review it carefully, then get your professor's permission before mixing your initial solution. Choose a chemical that is not too toxic to use with high school students.
To locate an MSDS, surf to http://www.ehs.psu.edu/hazmat/msds.cfm, then select one of the SIRI MSDS sites. Recently-purchased chemicals can be located by manufacturer. For older chemicals, you may not be able to find the original manufacturer's MSDS. In that case, locate an MSDS for the same chemical from another manufacturer. Often, the quickest way to find a chemical is to enter in the "Find" field a word from the manufacturer's name and a word from the chemical name, such as "Fisher Cupric." After you locate the MSDS, review it carefully and record the URL in your notes (you should include it in your written lab report). If you have selected a chemical other than the "suggested" chemicals, get the professor's permission before proceeding to Step 3.
3. Finally, prepare your serial dilution (Protocol 1) and set up the dose-response experiment (Protocol 2). If you use one of the "suggested" chemicals, refer to the Table 5 handout (packet distributed in class) for a suggested preparation of your "100% concentration." If you use another chemical, refer to the MSDS or the chemical's label before mixing your "100% concentration." You'll have trouble mixing a solution that exceeds the solubility of your chemical in water!
Some comments about academic integrity for this assignment:
a. You will carry out the experiment in groups of 2 students. Next week, you will prepare a written report online. You and your partner should report identical data in your data tables.
b. I encourage you to discuss your experiment and your findings with your partner. However, your written report should be your own work (other than your data tables). We expect that you are likely to reach conclusions similar to your lab partner. However, your written responses should be your own work. The submission of identical prose (or prose that has had just a few synonyms exchanged to make it "different") will be considered plagiarism.
c. If you have any questions about the balance that we expect between collaboration and individual work, please ask!