Adding less fuel, e.g., 15, 10, or 5 mM, shortened the reaction cycle and the maximum emission intensity of the dye. To ensure that the increased intensity originated from forming vesicles, we performed cryogenic transmission electron microscopy (cryo-TEM) imaging of the reaction mixture (Figure ). Excitingly, after 6 hours, we found multilamellar vesicles of irregular shape and polydisperse in size.