scholarly journals Multiplexed, High-Sensitivity Measurements of Antibody Affinity Using Interferometric Reflectance Imaging Sensor

Biosensors ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 483
Author(s):  
Allison Marn ◽  
James Needham ◽  
Elisa Chiodi ◽  
M. Ünlü

Anthrax lethal factor (LF) is one of the enzymatic components of the anthrax toxin responsible for the pathogenic responses of the anthrax disease. The ability to screen multiplexed ligands against LF and subsequently estimate the effective kinetic rates (kon and koff) and complementary binding behavior provides critical information useful in diagnostic and therapeutic development for anthrax. Tools such as biolayer interferometry (BLI) and surface plasmon resonance imaging (SPRi) have been developed for this purpose; however, these tools suffer from limitations such as signal jumps when the solution in the chamber is switched or low sensitivity. Here, we present multiplexed antibody affinity measurements obtained by the interferometric reflectance imaging sensor (IRIS), a highly sensitive, label-free optical biosensor, whose stability, simplicity, and imaging modality overcomes many of the limitations of other multiplexed methods. We compare the multiplexed binding results obtained with the IRIS system using two ligands targeting the anthrax lethal factor (LF) against previously published results obtained with more traditional surface plasmon resonance (SPR), which showed consistent results, as well as kinetic information previously unattainable with SPR. Additional exemplary data demonstrating multiplexed binding and the corresponding complementary binding to sequentially injected ligands provides an additional layer of information immediately useful to the researcher.

2007 ◽  
Vol 189 (19) ◽  
pp. 7154-7158 ◽  
Author(s):  
Judith Ferner-Ortner ◽  
Christoph Mader ◽  
Nicola Ilk ◽  
Uwe B. Sleytr ◽  
Eva M. Egelseer

ABSTRACT Surface plasmon resonance studies using C-terminal truncation forms of the S-layer protein SbsC (recombinant SbsC consisting of amino acids 31 to 270 [rSbsC31-270] and rSbsC31-443) and the secondary cell wall polymer (SCWP) isolated from Geobacillus stearothermophilus ATCC 12980 confirmed the exclusive responsibility of the N-terminal region comprising amino acids 31 to 270 for SCWP binding. Quantitative analyses indicated binding behavior demonstrating low, medium, and high affinities.


2009 ◽  
Vol 415 ◽  
pp. 77-80
Author(s):  
Doru Vornicescu ◽  
Katerina Solanska ◽  
Ioana Demetrescu ◽  
Matthias Frentzen ◽  
Michael Keusgen

: The pellicle on oral surfaces represents a central interface for the formation of biofilms. Among other things it causes the first adsorption of bacteria. The dynamics of pellicle formation, on tooth surfaces and the influence of oral therapeutics on the pellicle structure are fairly unknown. With the method of surface plasmon resonance (SPR), the formation of salivary pellicle structures on hydroxylapatite (HAP) surfaces covering a very thin (~50nm) layer gold on a glass prism was recorded in real time without labeling or destruction. As pellicle forming substrates natural pooled human saliva (NS) and artificial saliva (AS) were used. To simulate the influence of therapeutic additives on the dynamic of the pellicle forming process, a chlorhexidine preparate (Chlorhexamed Fluid® CHX) on two different concentrations was selected. The binding behavior of a NS and a preparation in terms of an AS were compared. The layer was largely stable against rinsing with buffer. The application of CHX preparations in two different concentrations as an example of an oral therapeutic additive revealed a complex dynamic of adsorption. CHX did not lead to any visible destruction of the pellicle. The introduced method is an excellent tool to illustrate the dynamic effects of pellicle formation or pellicle reorganization by measuring the increase or decrease of the SPR signal in real time.


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