To show the difference that the selection of a support grid optimally suited for high-powered illumination fluorescence imaging and subsequent cryo-TEM can make, we cultured human osteosarcoma (U2OS) cells expressing rsEGFP2-MAP2, a fusion of the green fluorescent protein rsEGFP2 that is known to efficiently photoswitch between bright and dark states at cryogenic temperature13, and MAP2, a microtubule binding protein, on 1.2/1.3 holey-gold 300 mesh gold grids (1.2/1.3 UltrAuFoil, Quantifoil). The gene discussed is MAP2; the disease is osteosarcoma.