title: Detection of opines by colorimetric assay.
abstract: A colorimetric procedure for confirming the presence of arginine-derived opines (nopaline and octopine) in plant tissue extracts is described. Those materials are widely used as markers of plant cell transformation and tumorigenesis mediated by the tumor-inducing plasmids of Agrobacterium tumefaciens. Nopaline and octopine are generally detected, following resolution by paper electrophoresis, by observation of the uv-fluorescent products formed upon reaction with phenanthrenequinone. We found that a further heat treatment step, compatible with paper electrophoresis, results in rapid production of a red-purple pigment. Our colorimetric assay is sensitive to 1.25-micrograms quantities of opine and eliminates problems of background fluorescence encountered with crude plant extract in the usual assay.
mesh_terms: D001120:Arginine / Q000031:analogs & derivatives* / Q000032:analysis; D002471:Cell Transformation, Neoplastic; D003124:Colorimetry / Q000379:methods*; D010941:Plant Tumors / Q000032:analysis; D010947:Plants, Toxic; D014026:Nicotiana
chemical_list: C008666:nopaline; C005394:octopine; D001120:Arginine