Improved species identification of raw meat by double sandwich enzyme-linked immunosorbent assay

An improved enzyme‐linked immunosorbent assay (ELISA) has been developed to enable differentiation of unprocessed beef, sheep, horse, kangaroo, pig, camel, buffalo and goat meats to less than 1% level of detection. This double sandwich system utilises species‐specific capture antibodies raised in sheep or cattle and coated on to microtitre plates. Antibody coated plates are then used to immunoextract soluble protein from prepared meat samples. Bound meat proteins are detected by the addition of species‐specific rabbit antisera followed by staphyloccocal Protein A conjugated to horse‐radish peroxidase (HRPO), or by antisera directly conjugated to HRPO. Adoption of a capture antibody provides a number of advantages over previously described ELISA systems. Sample preparation is not critical because colour production is approximately constant between sample dilutions of 1000 and 10 g litre−1. Increased sensitivity and selectivity allows the bulking of samples for screening purposes. In addition, the assay is faster; testing may be carried out in less than 2 h.