Direct imaging of antigen-antibody binding by atomic force microscopy

Jing Hu; Mingyan Gao; Zuobin Wang; Yujuan Chen; Zhengxun Song; Hongmei Xu

doi:10.1007/s13204-020-01558-w

Direct imaging of antigen-antibody binding by atomic force microscopy

Appl Nanosci. 2021;11(1):293-300. doi: 10.1007/s13204-020-01558-w. Epub 2020 Sep 24.

Authors

Jing Hu^{1

2}, Mingyan Gao^{1

2}, Zuobin Wang^{1

2

3}, Yujuan Chen^{1

2

4}, Zhengxun Song^{1

2}, Hongmei Xu^{1

2}

Affiliations

¹ Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.
² International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China.
³ JR3CN and IRAC, University of Bedfordshire, Luton, LU1 3JU UK.
⁴ School of Life Sciences, Changchun University of Science and Technology, Changchun, 130022 China.

Abstract

Direct observation of antigen-antibody binding at the nanoscale has always been a considerable challenging problem, and researchers have made tremendous efforts on it. In this study, the morphology of biotinylated antibody-specific Immunoglobulin E (IgE) immune complexes has been successfully imaged by atomic force microscopy (AFM) in the tapping-mode. The AFM images indicated that the individual immune complex was composed of an IgE and a biotinylated antibody. Excitingly, it is the first time that we have actually seen the IgE binding to biotinylated antibody. Alternatively, information on the length of IgE, biotinylated antibodies and biotinylated antibody-specific IgE immune complexes were also obtained, respectively. These results indicate the versatility of AFM technology in the identification of antigen-antibody binding. This work not only lays the basis for the direct imaging of the biotinylated antibody-IgE by AFM, but also offers valuable information for studying the targeted therapy and vaccine development in the future.

Keywords: Antigen–antibody binding; Atomic force microscopy; Biotinylated antibody-specific IgE immune complex; Imaging.