The stages of CSCs isolation by FACS. A - Solid tumour is digested by enzymes to cell suspension. B - Tumour cell suspension is incubated with antibodies directed against antigens specific for CSCs conjugated with fluorescent dye. C - The opsonized cell suspension is let through a narrow tunnel to form a single-cell-diameter stream. The vibration produces droplets containing single cells at the mouth of the tunnel. D - The droplets pass through a laser beam. The fluorescent dye is excited to emit the light identified by a detector. E - The detector is paired with the device which gives electrostatic charge to light-emitting cells. The “dark” cells remain uncharged. F - The flow of electrostatically charged cells is bent by the electric field. The cells are collected in the tube. The uncharged cells fall by gravitation.