what is pbs buffer

Phosphate-buffered saline (PBS) is a buffer solution commonly used in biological research. It is a water-based salt solution containing disodium hydrogen phosphate, sodium chloride, and, in some formulations, potassium chloride and potassium dihydrogen phosphate. The buffer helps to maintain a constant pH, and the osmolarity and ion concentrations of the solutions match those of the human body (isotonic). PBS has many uses because it is isotonic and non-toxic to most cells. It is commonly used to resuspend lyophilized powders of cell culture, dilute stock solutions to working concentrations, and as a wash buffer in various fields such as Western blotting, Enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, tissue dissociation, cell culture, hematological, and molecular biology procedures. PBS can be prepared by using commercially made PBS buffer tablets or pouches, and it can be stored at room temperature or in the refrigerator. PBS is also used for the recovery of cells and spermatozoa from swabs in forensic science laboratories