Quantitative analysis of tissues of the central nervous system in food products by GFAP-ELISA test kit. Results of an interlaboratory study

The results of an interlaboratory study are presented, with focus on the quantification of tissues of the central nervous system (CNS) in processed meat products by using an enzyme linked immunosorbent assay with glial fibrillary acidic protein as marker for CNS. Test materials with known amounts of CNS and subjected to several heat treatments were analysed by 21 laboratories. The concentration of CNS was calculated both by applying linear regression and polynomial fit. The results were evaluated by robust statistics and reveal linear regression to be a suitable method for quantification compared to polynomial fit with relative standard deviations for repeatability and reproducibility in the range 11–18% and 21–43% respectively; however, quantification can be difficult when the degree of heat treatment of the meat products is not known.