Open Access Nano Express

Probing Specific Interaction Forces Between Human IgG and Rat Anti-Human IgG by Self-Assembled Monolayer and Atomic Force Microscopy

Zhengjian Lv12, Jianhua Wang12*, Guoping Chen12 and Linhong Deng12*

Author Affiliations

1 Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, 400044, Chongqing, China

2 Institute of Biochemistry and Biophysics, College of Bioengineering, Chongqing University, 400044, Chongqing, China

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Nanoscale Research Letters 2010, 5:1032-1038  doi:10.1007/s11671-010-9598-x

Published: 14 April 2010

Abstract

Interaction forces between biological molecules such as antigen and antibody play important roles in many biological processes, but probing these forces remains technically challenging. Here, we investigated the specific interaction and unbinding forces between human IgG and rat anti-human IgG using self assembled monolayer (SAM) method for sample preparation and atomic force microscopy (AFM) for interaction force measurement. The specific interaction force between human IgG and rat anti-human IgG was found to be 0.6–1.0 nN, and the force required for unbinding a single pair of human IgG and rat anti-human IgG was calculated to be 144 ± 11 pN. The results are consistent with those reported in the literatures. Therefore, SAM for sample preparation combined with AFM for interaction measurement is a relatively simple, sensitive and reliable technique to probe specific interactions between biological molecules such as antigen and antibody.

Keywords:
Interaction; Human IgG; Rat anti-human IgG; Self assembled monolayer (SAM); Atomic force microscopy (AFM)