The Glycerol Lysis Test II buffer is suitable for testing the osmotic resistance of red blood cells. The inclusion of 85% glycerol in the composition increases the osmotic pressure on the cells, resulting in lysis. Potassium dihydrogen phosphate, disodium hydrogen phosphate dihydrate and sodium chloride form the buffer base, dissolved in highly pure water. The preservative sodium azide completes the formulation. A pH of 6.85 ensures an optimized environment for the glycerol lysis test, with ion concentrations supporting a controlled and repeatable test atmosphere. Altering osmotic pressure using different glycerol concentrations leads to a quantitative assessment of the osmotic resistance of red blood cells. This can provide insight into a variety of physiological and pathological conditions, making the solution a valuable tool in clinical diagnostics and life science.