PBS buffer pH 7.4 consists of a solution that is primarily used in medical diagnostics, histology and scientific research. The solution contains aqua bidest, di-sodium hydrogen phosphate dihydrate, potassium dihydrogen phosphate and sodium chloride. These are used to create a stable pH environment, which is essential for numerous biological and chemical reactions.

In detail, the PBS buffer is composed of NaCl, Na2HPO4-2H2O (di-sodium hydrogen phosphate dihydrate) and KH2PO4 (potassium dihydrogen phosphate). These chemical compounds make it possible to set a pH value of 7.4, which is close to the physiological pH value of human blood. Such an environment is critical for maintaining the functions of cells and proteins in biological samples.

The solution is often used to wash cells, prepare samples for microscopy, as a diluent for antibodies and for the incubation of cell cultures. The chemical reactions brought about by the use of the PBS buffer mainly concern the maintenance of osmotic balance and pH stability, ensuring an ideal environment for most cellular activities. A total molarity of about 0.01 M and an osmolarity close to 300 mOsmol/kg are present, with an average buffer capacity sufficient for standard laboratory work applications. In summary: essential for stable biochemical conditions.