Novel method for enriching and separating Candida albicans

Abstract

The invention discloses a method for enrichment and separation, and mainly discloses a method for enriching and separating Candida albicans. The method provides a basis for better follow-up research on a target fungus, and relates to the technical field of biology. The method comprises the following steps that: a multi-arm star polymer is covalently coupled with an antibody, an antibody-modified multi-arm star polymer further coats long-chain biotin molecules, the multi-arm star polymer jointly modified by the antibody and the long-chain biotin molecules captures target bacteria in sample liquid, streptavidin-modified nano magnetic beads identify and couple with a long-chain biotinylated multi-arm star polymer in the sample liquid, the captured bacteria is separated and suspended again, and the like. The separated target bacteria can be directly subjected to follow-up analysis, and in comparison with a conventional bacteria separation method, the method disclosed by the invention is more suitable for performing magnetic separation on the bacteria in a complex ground substance, and the separation efficiency of the target bacteria in the sample is improved.

Description

technical field [0001] The invention relates to the field of biotechnology, in particular to a method for isolating food-borne pathogenic bacteria based on nano magnetic beads. Background technique [0002] Candida albicans, also known as Candida albicans, is a fungus. In recent years, Candida albicans in the genus Candida is the most common among pathogenic nosocomial infection fungi. After Candida albicans infects the body, it can invade multiple tissues and organs throughout the body. It is very harmful and has a high fatality rate. It is particularly urgent to establish a new method for efficient and rapid detection of Candida albicans. In view of the need to establish an efficient and rapid detection method, immunomagnetic separation technology has been rapidly developed in the monitoring of foodborne pathogens. [0003] Immunomagnetic separation technology is one of the important components of the rapid screening technology for food-borne pathogens. This technology c...

AI Technical Summary

Problems solved by technology

However, the current separation technology based on micron-scale immunomagnetic beads has many limitations: 1) The specific surface area of ​​micron-sized magnetic beads is relatively small, which reduces the capture efficiency of magnetic beads; Bacterial cells are combined through a multiphase reaction (multiphase reaction), and it usually takes longer to specifically capture bacterial cells in the food matrix; 3) Micron magnetic beads have poor monodispersity and are prone to self-disruption in the food matrix solution. Aggregation or formation of precipitates; 4) Traditional immunomagnetic separation techniques often directly couple antibody molecules to immunomagnetic beads, which often leads to greatly reduced antibody activity and changes in the spatial direction of antibodies. The steric hindrance effect between antibodies reduces the capture efficiency of antibodies. 5) The nature of the food matrix is ​​complex and the concentration of non-target pathogenic bacteria is large. Micron magnetic beads are prone to non-specific adsorption, and it is difficult to realize the detection of food samples. Specific separation of target bacteria; 6) Too high concentration of micron magnetic beads will cause damage to bacterial cells (magnetic field causes magnetic beads on the cell surface to attract each other, causing cells to be squeezed or even ruptured), resulting in failure of separation; 7) Magnetic beads When coupling antibodies, hydrophobic adsorption or chemical coupling is generally used to couple active antibodies on the surface of magnetic beads

The distance between the antibody and the surface of the magnetic bead is too close, the nature of the magnetic bead itself and the residual hydrophobic or strong hydrophilic groups on the surface are likely to cause changes in the spatial conformation of the antibody, resulting in a decrease in the biological activity of the antibody

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