Abstract
As staple food of Japan, rice is widely distributed across the nation. In the event that rice is found at a crime scene, genomic information from a single grain could likely provide strong evidence for use in a criminal investigation. Although identification kits for rice cultivars are already commercially available, their utility in testing samples at a crime scene or in testing trace amounts of samples has not been investigated in sufficient depth. In this study, the performances of various DNA extraction and cultivar discrimination kits when one grain of rice was used were evaluated. Firstly, DNA samples were extracted using three commercial extraction kits from one grain of raw rice and one grain of boiled rice. Secondly, cultivar discrimination using extracted DNA samples was demonstrated using a commercial identification kit (Komebugyou, Kokken Co., Ltd.). The combined use of GM quicker 2 (Nippon Gene Co., Ltd.) and Komebugyou successfully identified all rice cultivars for both raw and boiled rice samples. The cultivar of a rice was also identified by the combined use of GM quicker 2 and Komebugyou when the rice was presented as fried rice, rice noodles, rice bread, and rice chaff. These results indicate that cultivar discrimination by Komebugyou can be applicable to trace amounts of rice products at a crime scene, and is strongly dependent on the DNA extraction kit used prior to discrimination.
