Bright field microscopy showing red onion cells in hypertonic solution. Hypertonic solutions contain high concentration of solute relative to the cells' cytoplasm. When the cells are placed in a hypertonic solution, the water diffuses out of the cells via osmosis, causing the cells to shrivel. Magnification 25x @ 35 mm. Image 1 of 3 (see 3Q3349 and 3Q3350 for isotonic and hypotonic solutions).