A Technic for Demonstrating Plasmodesma

Sections of potato tuber and epidermis from veins on the dorsal side of the sunflower leaf have proved most satisfactory in demonstrating plasmodesma. Kill fresh sections 5 minutes in a solution of 0.75 g. KI, 0.50 g. iodine in 100 cc. H2O. Swell 5 minutes in 10% H2SO4. Mordant 5 minutes in a solution of 1.25 g. KI, 1.00 g. iodine in 100 cc. of 5% H2SO4. Wash in 5% H2SO4 until iodine starts to fade. Stain in a mixture of 0.5% gentian violet solution in 5% H2SO4 made up to a deep green color. Wash in a solution of 30 cc. glycerin, 2 g. ZnCl2, 0.2 g. iodine, and a bit of KI in 60 cc. of water. Brush with a camel's hair brush, wash and mount in the same solution.