observing a colored cell under the microscope?

Question

when we get a colored cell under the microscope,than add a salt solution,5%, and then distilled water. I know that the color will first disappear and the come back but I just want a more detailed discription of why this happens...

Answer 1

the salt water is a hypertonic solution compared to the cell. this will cause the water to leave the stained cell by a process called osmosis. water is an universal solvent, this means the stain is actually dissolved in the water. so when osmosis occurs and exits the cell then the dye exits as well. when the distilled water is added this creates a hypotonic solution. this causes the water to flow back into the cell and thus taking the dye back into the cell.