An improved protein extraction method for detecting ruminant material in feed using lateral flow device dipsticks

Abstract

The currently used immunological lateral flow based dipstick technology is not sensitive to detect the presence of ruminant animal material below 1% level of contamination in feed. The possible reason is that the processed animal proteins are subjected to chemicals and to high temperatures during the rendering process, thereby leading to either their denaturation or degradation. Also some feed samples producing viscous extracts or containing high contents of mineral or vitamins delay the migration flow in the test device and may thus give rise to either inconclusive or false positive results. Veterinary Laboratory Agency focused its efforts on developing a new protein extraction method through the EU Safeed-PAP project with the aim to increase the sensitivity of the dipstick method. The method developed is based on a bone sedimentation procedure coupled with an EDTA digestion step in order to liberate the protected proteins which are covalently bound to mineral structures within the bone mineral cage. All the results using this method showed that the feed contaminated with ruminant material is detected at 0.1 to 0.2% levels.

Keywords

• Protein extraction
• ruminant proteins
• lateral flow device
• dipstick method
• bone sedimentation
• bone digestion