Real-Time Detection of Antigen–Antibody Reactions by Imaging Ellipsometry

Irina Chamritski; Mark Clarkson; Jeff Franklin; Shi Wei Li

doi:10.1071/CH07115

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Real-Time Detection of Antigen–Antibody Reactions by Imaging Ellipsometry

Irina Chamritski ^A ^C , Mark Clarkson ^A , Jeff Franklin ^B and Shi Wei Li ^A

+ Author Affiliations

- Author Affiliations

^A Industrial Research Limited, PO Box 310310, Lower Hutt, New Zealand.

^B Axela Biosensors Inc., 480 University Ave., Suite 910, Toronto, ON, Canada.

^C Corresponding author. Email: i.chamritskaia@irl.cri.nz

Australian Journal of Chemistry 60(9) 667-671 https://doi.org/10.1071/CH07115
Submitted: 19 April 2007 Accepted: 9 August 2007 Published: 11 September 2007

Abstract

In the field of proteomics the quantification of the affinity of an antibody to its partners and the evaluation of its specific binding is an important issue. With an imaging ellipsometer the interaction of an antibody with immobilized antigens on a model microarray is observed in a time-resolved and label-free manner. Imaging ellipsometry was developed for real-time monitoring of the biomolecule interaction between an antigen in solution and an antibody immobilized on a silicon surface. Proteins were immobilized by the formation of carboxy-alkyl monolayers on silicon substrates, where a biotin-labelled antibody was immobilized by a biotin–streptavidin linkage. Anti-human IgG bound specifically to human antibody and protein A, similarly anti-goat IgG bound to goat antibody. No binding was observed between anti-rabbit IgG and goat antibody. All stages of the formation of the antigen–antibody complex were imaged by imaging ellipsometry. By monitoring changes in y, the mole fraction θ of the antigen–antibody binding was determined. Immunological reactions of two different antigen–antibody combinations were fitted by the Langmuir adsorption equation, and affinity constants for two reactions were calculated.

Acknowledgement

This research was supported by the Foundation for Research Science and Technology, New Zealand (contract number IRLX0401).

References

Real-Time Detection of Antigen–Antibody Reactions by Imaging Ellipsometry

Abstract

Acknowledgement

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