Chloroplastic (NADP(+)) glyceraldehyde-3-phosphate dehydrogenase (E.C. 1.2.1.9) catalyzes the second reaction in photosynthesis after the fixation of carbon by RuBisCO. Chloroplast-bound (NADP(+)) G3PDH was resolved in soybean by starch gel electrophoresis using L-histidine-citrate buffer (pH 5.7).