Subcellular fractionation to detect nuclear translocation of GR protein in xenograft cells. Nuclear translocation of GR protein was confirmed in our entire panel of xenografts by subcellular fractionation followed by immunoblot analysis. Xenograft cells were retrieved from cryostorage, exposed to dexamethasone (1 μM, 5 hours), and subjected to subcellular fractionation. Equal amounts of protein (30 μg) from cytoplasmic (C) and nuclear (N) fractions were separated by SDS-PAGE. Membranes were probed with antibodies against GR, actin (loading control), Bax (cytoplasmic control), and topo I (nuclear control).