Saltatory rolling circle amplification (SRCA) for sensitive visual detection of horsemeat adulteration in beef products

Meat adulteration is a form of economic fraud and a global issue diminishing consumer confidence. Consequently, a sensitive and reliable technique for meat species identification is needed to protect meat quality. The present work proposes a rapid, nucleic acid, isothermal amplification method, with SYBR Green I visualization called saltatory rolling circle amplification (SRCA) to identify horsemeat in beef products. Primers were designed to specifically amplify the mitochondrial cytochrome b gene regions of different lengths of horsemeat DNAs. Fresh muscle tissue samples from ten different species were used to confirm the specificity of SRCA. The sensitivity of SRCA was evaluated and found to be 6.3 x 10(1) fg/mu L. The detection limit of SRCA was 0.01% when evaluated with artificially contaminated beef in horsemeat. Compared with conventional PCR approaches, SRCA assay achieved at least 100-fold higher sensitivity and tenfold lower detection limits. In addition, the sensitivity, specificity, and accuracy of the SRCA system were calculated to be 100.00, 98.41, and 98.48%, respectively. Consequently, the present study offers a highly sensitive and visual technique for determining meat adulteration by discriminating horsemeat.