Development and validation of isothermal polymerase spiral reaction assay for the specific authentication of goat (Capra hircus) meat

Abstract

Goat meat (chevon) is one of the costlier meats and closely resembles other red meat species mostly the sheep meat (mutton). In order to establish authenticity of chevon and confirm mislabelling there is a need for a reliable laboratory test. Polymerase spiral reaction (PSR) assay is one of the recent DNA based isothermal tests available for molecular analysis mostly microorganisms. Present study describes development and validation of a novel PSR for the detection of chevon for the first time. The goat specific PSR makes use of a pair of chevon-specific primers targeted against the mitochondrial DNA and test could be read based on the visual colour change after the addition of SYBR Green I dye to the amplified product. The possibility of cross-amplification was ruled out by testing related meat species ( buffalo, cattle, chicken, pig, sheep, and ostrich) and results of PSR were further confirmed by fluorometry and agarose gel electrophoresis. PSR could be undertaken at isothermal temperature of 62 °C temperature for 60 min with the limit of detection of 0.5 ng DNA and detection of meat admixing of 0.1%. The PSR was found efficient in the detection of not only raw meat but also meat heated to 121 °C for 30 min. When combined with the alkaline lysis method of DNA extraction, the goat-specific PSR takes only 90 min of sample analysis time and could be used for the rapid analysis of field samples.