Extraction of starch by dimethyl sulfoxide and quantitation by enzymatic assay.
A method for the rapid, sensitive, and specific determination of starch in plant tissues is described. Starch from a variety of plant tissues is solubilized by stirring for 24 h or by sonication for 40 min in dimethyl sulfoxide. Dilution of this extract to less than 20% dimethyl sulfoxide permits a nearly complete hydrolysis of the starch in less than 3 h with glucoamylase from Rhizopus niveus. Quantitation of liberated glucose by a coupled hexokinase and glucose-6-phosphate dehydrogenase method provides an additional degree of specificity.
D000687:Amylopectin / Q000032:analysis; D000688:Amylose / Q000032:analysis; D004121:Dimethyl Sulfoxide; D005087:Glucan 1,4-alpha-Glucosidase; D005947:Glucose / Q000032:analysis; D005954:Glucosephosphate Dehydrogenase; D006593:Hexokinase; D006868:Hydrolysis; D010944:Plants / Q000032:analysis; D013213:Starch / Q000032:analysis*
D013213:Starch; D000688:Amylose; D000687:Amylopectin; D005954:Glucosephosphate Dehydrogenase; D006593:Hexokinase; D005087:Glucan 1,4-alpha-Glucosidase; D005947:Glucose; D004121:Dimethyl Sulfoxide