Quantitative determination of starch, amylose, and amylopectin in plant tissues using glass fiber paper.

Methods for accurate and rapid determination of starch, amylose, and amylopectin in plant tissues are described. They are based on simplified extraction of starch with 32% perchloric acid and selective retention of the starch-iodine complex on a glass fiber disk (Whatman GF/A). The starch on the disk is dissolved in 0.75 M sulfuric acid and estimated with phenol. For amylose and amylopectin determination the starch on the disk is dissolved in perchloric acid, precipitated with ethanol, and retained on a 10-cm glass fiber strip. Both polysaccharides are separated by a chromatographic procedure involving development of the strip in a mixture of ethanol and dimethyl sulfoxide and in dimethyl sulfoxide. The strip is washed in ethanol and stained with iodine or used for polysaccharide quantitation. As little as 5 micrograms of starch or its components present in different amounts of plant material can be estimated.