Classroom Experiments
Saponin Shake Test Caterpillar Experiment Alfalfa and Saponin Caterpillar Experiment Nicotine	Dyer, L.A. and G.L. Gentry. 2002. Caterpillars and parasitoids of a tropical lowland wet forest. http://www.caterpillars.org. Accessed: (June 27,2005). Saponin Shake Test Background: Saponins are ‘soapy’ chemical compounds found in the leaves of plants that help plants defend against herbivores and fungus. Some saponins are harmful to humans while others are beneficial like aloe plants. Saponin quantities are an easy and fun experiment to complete with students. Objective: To measure the level of saponins in leafy material. Grade Level: 3^rd – 12^th Materials: Fresh leaves Water Hotplate 100 ml beaker 100 ml graduated cylinder Time: 45 – 60 minutes
	Procedures: Tear 1 gram of fresh leaf material into pieces Put into 100 ml beaker Add 15 ml of Water Boil 10 minutes loosely covered Pour liquid into graduated cylinder Measure liquid extract (in ml) Add extract to 10 ml of water in a 100 ml graduated cylinder Shake 30 times Measure foam in ml at 0 minutes, 1 minute, 5 minutes Record answers
	Questions you can pose to students: Are there different saponin levels in different plants? Will younger leaves of a plant have more or less saponin? As plants get older do they put more resources into producing saponin for their leaves or less? Extensions: One reason scientists study saponins is to understand the relationship between herbivores and plants. You could vary any of the following conditions and measure the saponin level in each experiment. Changes in the following conditions affect a plants natural defense mechanism. One defense mechanism a plant has is to vary the amount of saponins in its leaves. Soil conditions Fertilizer CO2 Damage to leaves possibly caused by herbivores (caterpillars) Temperature Water Toxicity in soil Caterpillar Experiment - Alfalfa and Saponin Caterpillar Experiment - Nicotene