Abstract:

[Abstract]   Objective   To explore a novel quantitative detection method for the concentration of specific IgG (sIgG)
in food intolerance, taking egg sIgG detection for the example.  Methods  A total of173patients underwent food allergen sIgG detection were included in this study, and 78healthy subjects were used as negative controls. The microtiter plates were coated with biotinylated bovine serum albumin (BSA) and linked with streptavidin. Then, the biotinylated egg antigen and specimen were successively added into the wells of plate．After washing, enzyme labeled anti-human IgG was added to establish an antigen indirectly coated liquid-phase reaction patterns of ELISA method. The concentration of the biotinylated allergens and enzyme labeled antibody were optimized and the reaction conditions were determined. This method was used to detect the sIgG in serum samples.  Results  The biotinylated egg white was selected as antigen, the optimal dilution rate was 1∶2000，and the most suitable enzyme labeled antibody dilution ratio was1∶12000in this method. The within-run and the between-run coefficients of variation were4.83%-8.55% and4.88%-7.93% respectively. The specificity is preferable, the species-crossed reaction rates with crab, cow milk and goat milk were <10%. There was a good correlation between the assay developed in this study and the food intolerance detection kit provided by United States BIOMERICA Inc ( =0.977X+8.45,r=0.961, P<0.05).   Conclusion   The detection method can be used to detect serum sIgG for egg intolerance patients with easy operation, highly accuracy and specificity. Furthermore, it showed the capacity of excellent repeatability and flexibility potential, which provided a good foundation for developing a kind of“personalized”random combination of food varieties ELISA kit.

Key words: Food intolerance, specific IgG, enzyme-linked immunosorbent assay, biotin- streptavidin, egg