The research organization utilizes nano magnetic beads with a particle size of 100-800nm and Salmonella specific antibodies, and prepares immunomagnetic beads for Salmonella capture and separation through carbodiimide condensation, thus forming a product of Salmonella immunomagnetic beads which has currently been popularized in the market. The capture efficiency of target bacteria is 90%, which is higher than that of similar products in the market by more than 20%. Salmonella immunomagnetic beads are applied to the fast detection of Salmonella in milk, and the specific immune capture of target bacteria in samples is performed to optimize the pretreatment process of routine detection of Salmonella. After a short time (3h) of enrichment of target bacteria acquired by magnetic separation, the detection of Salmonella pathogens in milk can be completed within 6 hours on the strength of fluorescence quantitative PCR technology, and the detection limit is 1-10 CFU/25g, which is 96 hours (4 days) shorter than that of the national standard method. Advantages of immunomagnetic beads technology: the immunomagnetic beads prepared by monodisperse magnetic microspheres with a particle size in the range of 100-800nm have larger specific surface area, which is beneficial to fix more antibodies, tremendously increasing the surface antigen binding sites. It is more suitable for the immune recognition and capture of micro-biological macromolecular antigens, and substantially enhances the immune recognition performance of microorganisms. The capture accuracy of Salmonella immunomagnetic beads for 1-10 CFU/mL is up to 100%.

Technical advantages of detection method: the research organization makes immunomagnetic separation of Salmonella, and then performs short-term enrichment of target bacteria; the superiority of this technology enables the target bacteria to be separated from a large number of miscellaneous bacteria and proliferated in a short period of time, which not only increases the accuracy and sensitivity of the detection method, but dramatically shortens the pretreatment time. The fluorescence quantitative PCR technology itself is provided with fast and accurate advantages, and when combining the fluorescence quantitative PCR technology with the advantages of immunomagnetic separation technology, the detection method becomes faster, more accurate, specific and sensitive. The preparation technology of immunomagnetic beads and immunomagnetic separation technology can efficiently capture trace targets in complex and turbid biological/environmental samples, improve the sensitivity and applicability of the detection method, and boast broad application prospects in sensitive detection of trace harmful substances in medical diagnosis, food safety, environmental analysis and other fields. (2) As a pretreatment technology, the immunomagnetic separation technology established can not only be combined with PCR technology, but integrated with other detection technologies, such as LAMP, digital PCR, ELISA, etc., which makes all types of detection technologies to be applied more strongly in a wider range.

Intellectual Property Rights and Awards:

The project has acquired 1 patent, and won the Science and Technology Award (Youth Award) of China Association for Instrumental Analysis (CAIA) and the 2014 Outstanding Scientific and Technological Achievement Award of Beijing Academy of Science and Technology.