Isolation of Plant Cuticles With Zinc Chloride-hydrochloric Acid Solution.

rhe cuiticle of plants is a heterogenous memnbranie in which wax, pectin and cellulose in varying l)ro)ortions are contained in a cutin franmework. In the isolation of cuticular membranes from leaves or fruits the wax is nornially removed by extraction xvith ani organic solvent before detachment of the memnbranes from the underlying epidermal cells. Detachnmenit is achieve(d by the use of either ammoium oxalate/oxalic acid solutioln (1) or l)ectic enzymes (2) both of which attack pectin occtirrinig where the membrane merges with the outer epidermal cell wall. Cellulose may be subsequently remiioved froni the isolated membranes by treatnmelnt witlh cul)ralnnlonium ( 3 ) or zinc chloride-hydroebloric acid (4) solution;s. We have found durinig ail examination of a wide range of plants that the pectic enzyme and ammoiiium oxalate/oxalic acid methods completely failedl to detach either upper or lower membranes from certain leaves., With many leaves a partial or total (lisintegrationi of both membranes occurred (luritng (letachment. In other cases the uppel or lowel miembrane onlwas release(l. Somiie of these effects have beeln reported by Orgell (2) uising pectic enzymes. He suggested thlat cuiticular menmbranes wvere more readilv releasedi frolmi leaves in which