Development of a rapid and accurate PCR-based detection method for commercially valuable green algal species

Abstract

We developed a rapid and accurate PCR-based inspection technique for individual detection of five commercially important green algal species, Ulva linza, U. prolifera, U. intestinalis, U. compressa and Monostroma nitidum, all of which are controlled as import quota items in Japan. This analytical method has solved the general problem of PCR-based detection methods of being defenseless against false-negatives by application of a duplex PCR technique with an internal control band generated by a set of universal primers for green algal species. Due to the detection of small-sized PCR products of <250 bp lengths, the analytical method would be useful for deeply processed products and completes its quick PCR amplification within 45 min. The validity of the developed analytical method was proved by a pre-test using a total of 129 samples (12 imported products and 31 Japanese commercial products). This analytical method is a powerful tool for screening of commercial green algal products to discover the five controlled algal species and will allow inspection authorities, including the Customs Service, to improve their examination systems in terms of simplification, rapidity and cost-effectiveness.