As good forensic scientists you will use controls in all of your experiments. A controlled experiment compares the results obtained from an experimental sample to a control sample, which is identical to the experimental sample except for one variable whose effect is being tested. There are two types of controls. A negative control is designed to not react to the test. In this lab, the negative control simply shows the absence of the macromolecule we are testing for. In contrast, a positive control is expected to give you a reaction with the test. For this lab it shows you that your indicator is functioning properly with the appropriate macromolecule. In order to solve the case, we must test for the presence of simple sugars, starch, protein sand fats. Objectives: Become proficient in testing for simple sugars, starches, lipids, and proteins. Interpret test results to identify the likely perpetrator of the State Fair Killing. Large molecules like these cannot be identified with the naked eye. Examine the unknown sample provided. Can you spot the protein, fat, sugars, or starch? Simple chemical procedures can test for these molecules. As forensic investigators, we will use chemical tests to detect specific organic molecules, including carbohydrates, lipids, and proteins. Indicator Solutions are used to identify specific molecules: IKI (Iodine) tests for starch, Benedict's Solution tests for reducing sugars, The Biuret Test identifies protein, Sudan IV tests for fats and oils