Dulbecco's Phosphate Buffered Saline (DPBS) is intended to provide a buffer system for maintaining cell culture media in the physiological range of 7.2-7.6. It's utility in maintaining mammalian cells when a chemically-defined, balanced salt solution provides the appropriate milieu to sustain the physiological and structural integrity (i.e. tonicity/viability) of cells in vitro for a limited period of time.
Balanced Salts are generally utilized to maintain cells for the short term in a viable condition rather than to promote their growth while the cells are manipulated outside of their regular growth environment. During these intervals, the cells maintenance requirements are such that osmotic balance and physiological pH are at the forefront as such isotonic solutions like DPBS without Calcium and Magnesium protects the cells from acute fluctuations, likely encountered, during laboratory manipulations.
The current role of Phosphate Buffered Saline in cell culture is multi-faceted and can be divided into four-fold principal functions:
- Provides cells with water and certain bulk inorganic ions essential for normal cell metabolism.
- Serves not only as an irrigating and transporting fluid, but also as a diluent (i.e. especially in cell enumerations) while maintaining osmoregulation, the optimal and constant balance of osmotic pressure gradients between the intracellular and extracellular compartments.
- Provides a Buffering System to support the medium within the physiological range of 7.2-7.6When combined with a carbohydrate (CHO) such as Glucose (C6H12O6),it provides the principal energy source for Cellular Metabolic Processes.