Plasma

Definition: The clear, yellowish liquid portion of blood or lymph, in which red blood cells, white blood cells, and platelets are suspended. Plasma differs from serum in that it contains clotting elements, such as fibrin, dissolved within it. Plasma may be separated from whole blood by the use of a rapidly spinning device called a centrifuge, which causes the solid portion of whole blood (blood cells and platelets) to settle to the bottom, separating them from the liquid plasma and substances dissolved within it.