What is left when you remove plasma from whole blood?

Removing plasma from whole blood results in the separation of red blood cells (RBCs), white blood cells (WBCs), platelets, and other blood components. The remaining substance is known as packed red blood cells or packed cells. Packed cells primarily consist of concentrated RBCs, which carry oxygen throughout the body and remove waste products like carbon dioxide. When whole blood is centrifuged, the denser RBCs settle at the bottom, forming the packed cell layer. The plasma, containing proteins, electrolytes, hormones, and other solutes, is located above the packed cells.