Red Blood Cell Depletion Magnetic Beads can be used for separation of Red Blood Cells, from whole blood. Remaining white blood cells can be used for downstream assays such as immunoassays, Western blots, FACS, and immunohistochemistry. For 100 µL of whole blood cells add 75 µL of Depletion beads, expecting 75 – 95% depletion of RBC after one pass. Optimal amount for applications should be determined by the researcher.