The product was tested on Xenopus retinal ganglion cells (RGCs), which respond to bath application of Sema3A through collapse of their growth cones (visible under 20X magnification) and retraction of the axon, as it is a repulsive guidance cue. Explants were dissected from Xenopus embryos at either Stage 35/36 or Stage 37/38 and cultured for 24-26 hours before experimentation. At this stage, and for this period of culture, both are known from literature to be sensitive to Sema3A.