The SÖRENSEN buffer pH 7.2 is frequently used in medical diagnostics, histology and scientific laboratories, especially where a stable pH environment is required for enzymatic reactions and other sensitive biological processes. This solution contains 1000 ml Aqua dest. / deionized water, 2.487 g potassium dihydrogen phosphate and 8.624 g di-sodium hydrogen phosphate dihydrate. The mixture is supplemented by the addition of 2 ml of a 10 % sodium azide solution, which serves as a preservative. Potassium dihydrogen phosphate (KH2PO4) and di-sodium hydrogen phosphate dihydrate (Na2HPO4-2H2O) play a central role in buffering. As soon as these salts are dissolved in water, they dissociate into their respective ions, which support pH stability in the range of approx. 6.8 to 8.0. Such buffers are essential for experiments that require precise pH control. In practical applications, the buffer solution creates a constant environment, which is important for the increased reproducibility of experiments. The molarity of this solution is about 0.018 mol/L for KH2PO4 and about 0.05 mol/L for Na2HPO4-2H2O, which enables an effective buffering effect. The osmolarity, a measure of osmotic concentration, is in a range compatible with cellular conditions and the buffering capacity is sufficient to counteract pH fluctuations. This buffer solution guarantees pH balance in biochemical procedures.