A group of Japanese companies claim to have developed a new technology to accurately determine the percentage of genetically modified ingredients in imported corn and soy beans. Nippon Flour Mills Co, Asahi Breweries Ltd. and Japan's National Food Research Institute, the last linked to Japan's Ministry of Agriculture, Forestry and Fisheries. The technology uses plasmids, rings of DNA molecules that are used in recombinant gene technology. In tests involving samples containing a mixture of five varieties of gene-altered corn, DNA was extracted, amplified and then measured so that even a 0.1% presence of a gene-altered corn strain could be measured. The companies intend to offer the test in kit form to testing organisations. The new technology coincides with the new law in Japan, starting in April 2001, that will require food producers to label products containing genetically modified organisms.