Diffusion across a Selectively Permeable Membrane

Lab groups fill a section of dialysis tubing with glucose and starch solutions and suspend it in a water bath. They use iodine as a starch indicator and a glucose test strip to find out if either of the materials crossed the selectively permeable membrane into the water. This classic experiment is laid out in a way that keeps biologists on target and engaged in the learning experience. Photos and diagrams help make the concepts clear.