[Study on positive control for GM papaya (55-1) detection method by GUS (beta-glucuronidase) assay]

A suitable positive control was investigated for histochemical assay (GUS-examining method) to detect genetically modified (GM) papaya (55-1), currently undergoing a safety assessment in Japan. Six different kinds of test papers were soaked with beta-glucuronidase solution and examined for GUS activity. The test papers made of nylon and glass fiber turned blue, and were stable for fifteen months at -20 degrees C. They are concluded to be useful as positive controls in the GUS-examining method for inspection of GM papaya (55-1).