How PBS washed red blood cell?

To wash red blood cells (RBCs) using phosphate-buffered saline (PBS), the cells are first centrifuged to separate them from their plasma. The supernatant is discarded, and the RBC pellet is resuspended in PBS, which helps maintain their pH and osmotic balance. This suspension is then centrifuged again, and the supernatant is removed, repeating the process as needed to remove contaminants or plasma proteins. The final washed RBCs can then be used for various laboratory applications.