High-efficiency transformation of Poinsettia protoplasts. Lower leaf surface after protoplast release through cellulose digestion. 5 × 105 Poinsettia Protoplasts were transformed with 0.7 μg of a DNA construct for constitutive expression of Yellow Fluorescent Protein. YFP expression was visualised after overnight incubation, using a UV microscope. Left: brightfield; right: UV.