blood specimen peripheral blood mononuclear cell specimen PBMC specimen A processed specimen that is extracted from whole blood using gradient centrifugation that separates the blood into a layer of peripheral blood mononuclear cells under the top layer of plasma. It contains lymphocytes, monocytes or macrophages that are critical components in the immune system. Chris Stoeckert Jie Zheng peripheral blood mononuclear cell specimen http://en.wikipedia.org/wiki/Peripheral_blood_mononuclear_cell metadata complete