- Read the instructions for Membrane Integrity Lab, and complete the following worksheet.
You will look at the resistance of the membrane to the effect of ethanol that impairs the membrane integrity and makes it permeable for variable solutes. Specifically, we will be looking at the release of a red pigment, betacyanin, from beet cells. Normally this pigment is stored in the central vacuole of beet cells and cross the membrane that surrounds the vacuole. When the integrity of the plasma membrane and intracellular membranes (including the membrane of the vacuole) is compromised, the pigment gets released from the cells. Since this pigment is read, we will be able to detect by using a spectrophotometer.