Fig. 1

a The establishment of human GBM primary cell culture. b Isolation of tumor neurospheres derived from GBM primary cell culture. d Purification of GBM cells from tumor subspheres using CD133 microbeads. Immunophenotypic characterization by using flow cytometry to evaluate the efficiency of magnetic cell separation for the antigenic marker, CD133 (76.3%). e–h CD133⁺GBM cells were able to further generate subspheres, compared with the absence of subspheres obtained from CD133⁻ fractions (c). e, f GBM subspheres visualized by inverted microscopy. g, h GBM subspheres visualized by fluorescence microscopy. i–k TEM of the GBM subspheres. l–q TEM of the CD133⁺ stem cells. n = nucleus, c = cytoplasm, mi = mitochondria, rer = rough endoplasmic reticulum, pv = pinocytic vesicles, v = vacuoles, arrow = electron-dense granules or magnetic beads. Scale: i–k 5.0 μm, l 2.0 μm, m–q 1.0 μm. r Fluorescence detection of Qdots (705 nm) labeling in the CD133⁺ GBM cells. s Fluorescence detection of Qdots (705 nm) labeling in the CD133⁺ GBM cells and DAPI. Magnification: ×400. All figures are representative ones from assays performed at least five times