A phosphate-buffered saline solution serves as a fundamental component in flow cytometry. This isotonic solution, typically composed of sodium chloride, sodium phosphate, and, in some formulations, potassium chloride and potassium phosphate, maintains a stable pH and osmolarity, mimicking physiological conditions. Its primary role is to suspend cells or other biological samples during the analysis process, ensuring that cells remain viable and retain their native properties. For instance, cells stained with fluorescent antibodies are often washed and resuspended within this solution prior to their introduction into the flow cytometer.
The significance of this buffered solution stems from its ability to minimize cell damage and aggregation, both of which can negatively impact the accuracy and reliability of flow cytometry data. By providing a stable and compatible environment, it prevents osmotic shock and preserves cellular integrity. Its use dates back to the early development of flow cytometry and has become a standardized practice, contributing substantially to the reproducibility and robustness of experimental results. Its well-defined composition and buffering capacity make it an invaluable reagent in cell-based assays.
