PBMC, or peripheral blood mononuclear cells, are comprised mainly of lymphocytes and monocytes. They are found circulating in whole blood and are readily separated by centrifugation. The PBMC layer collects underneath the top layer of blood plasma. As a major source of white blood cells, PBMC serves as an important starting material in biomedical and clinical applications. Ready-to-use kits offer a rapid and reliable option of PBMC isolation from whole blood through proven density and magnetic separation methods.