The whole blood with solutions of different concentrations mixed in order to find the tonicity of each solution.
Osmosis is the movement of water from the high solvent concentration to low solvent concentration. The solution on addition of the red blood cells becomes opaque and the cells can be observed under the microscope. If the solution is hypertonic, the red blood cell loses water and undergo shrinkage. If the solution is isotonic, the water flow will be at equal rates and the cell will remain intact. If the solution is hypotonic, the water will flow into the cell causing the cell to swell up.
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