When Molecules Kiss, We Tell
Understanding and measuring molecular binding remains a critical component of biochemical research, drug discovery, and diagnostics development. Despite enormous emphasis on collecting biologically relevant binding affinity data, many existing methods struggle to sensitively measure these interactions through chemical manipulation of one or more binding partner. While other more complex methods improve on this point, none of these accomplish this task without significant method development, cost, and data analysis. To meet this need, Meru Biotechnologies’ Compensated Backscattering Interferometry (CBSI) builds on the strengths of existing label-free methods, while eliminating their individual challenges.
Compensated Back Scattering Interferometry (CBSI)
The accurate and sensitive measurement of molecular interaction in native environments is a large problem. Assay sensitivity regardless of the methods are negatively impacted by complex sample interference, auto fluorescence, high signal to background noise, false negatives and false positives.
Meru is changing the game.
CBSI is a label-free, and free solution assay technology for measuring molecular interaction. The study of proteins often involves immobilization, labelling, fractionation and removal from native environment depriving them of substances needed to function properly. CBSI quantifies the interaction of molecules in solution without labeling, immobilization, tethering or special impedance plates.
Meru Biotechnologies’ CBSI combines the strengths of existing label-free approaches in a straightforward analytical platform, powered by advancements in Compensated Back Scattering Interferometry, which uses a single laser to measure experimental and reference samples in the same microfluidic channel simultaneously. CBSI’s unique signal transduction mechanism, which detects changes in molecular conformation and hydration that in turn alter its dielectric constant and RI, enables sensitivity that rivals methods that use fluorescence and eliminates the need for surface immobilization strategies needed in SPR and BLI. Furthermore, CBSI is pair agnostic, does not require mass addition, and can be performed in both complex matrices and entrained membrane receptors. These features collectively add to the biological relevance of CBSI data output.
Instead of measuring RI changes due to mass adsorption or optical thickness, CBSI measures RI changes in solution that are a direct result of molecular binding. When a chemical pair recognize each other, conformational, molecular dipole/electronic structure, and hydration changes occur that collectively impact a solution’s RI. These RI changes are detected through analysis of high-contrast interference fringe patterns that are produced by a laser interacting with a capillary or channel in a chip. The fringes are collected using a charge-coupled device (CCD) array detector. A select region of interest (ROI), composed of ~7 fringes, that exhibits a single spatial frequency is then analyzed using a Fourier Transform. When the RI/dipole changes following binding, positional shifts in this single spatial frequency (phase change) occur that are proportional to the interaction. Using CBSI, between 10-3 and 10-7 RI changes can be reliably detected, when compared with a reference sample lacking one binding partner.1,5 As a result, CBSI permits sensitive recognition of a binding event or detection of an analyte with numerous advantages over existing methods. These advantages include lower LOQs than many best-in-class assay systems and opportunities to study native binding for drug discovery, diagnostic endeavors, and clinical applications.
Use CBSI to:
Determine Physiologically Relevant Drug Binding Affinities
Improve In Vitro In Vivo Correlation (IVIVC)
Measure Protein-Protein Interactions
Measure Protein-Ion Interactions
Measure Protein-Small Molecule Interaction
Quantify Blood Serum Biomarkers
Rapidly Detect and Quantify Low Abundance Chemicals in Crude Human Samples
Benefits of CBSI:
CBSI enables fast assay development time.
CBSI accommodates virtually any sample type including aqueous and inorganic buffers, serum, tissue culture media, cell extracts, tissue homogenates, urine and saliva.
CBSI provides exceptional sensitivity (fM, 10-15 pg/mL) without sacrificing reproducibility.
CBSI is more predictive of native protein behavior.
Mizuno H, Kihara Y, Kussrow A, Chen A, Ray M, Rivera R, Bornhop DJ, Chun J. Lysophospholipid G protein-coupled receptor binding parameters as determined by backscattering interferometry. J Lipid Res. 2019 Jan;60(1):212-217.
Kammer M, Kussrow A, Carter MD, Isenberg SL, Johnson RC, Batchelor RH, Jackson GW, Bornhop DJ. Rapid quantification of two chemical nerve agent metabolites in serum. Biosens Bioelectron. 2019 Apr 15;131:119-127
Kammer MN, Kussrow AK, Webster RL, Chen H, Hoeksema M, Christenson R, Massion PP, Bornhop DJ. Compensated Interferometry measures of CYFRA 21-1 improve diagnosis of lung cancer. ACS Comb Sci. 2019 Jun 10;21(6):465-472.
Kammer MN, Kussrow AK, Olmsted IR, Bornhop DJ. A Highly Compensated Interferometer for Biochemical Analysis. ACS Sens. 2018 Aug 24;3(8):1546-1552.
Wang M, Kussrow AK, Ocana MF, Chabot JR, Lepsy CS, Bornhop DJ, O'Hara DM.Physiologically relevant binding affinity quantification of monoclonal antibody PF-00547659 to mucosal addressin cell adhesion molecule for in vitro in vivo correlation. Br J Pharmacol. 2017 Jan;174(1):70-81.
Bornhop DJ, Kammer MN, Kussrow A, Flowers RA, Meiler J. Origin and prediction of free-solution interaction studies performed label-free. Proc Natl Acad Sci U S A. 2016 Mar 22;113(12):E1595-604.
Saetear P, Perrin AJ, Bartholdson SJ, Wanaguru M, Kussrow A, Bornhop DJ, Wright GJ. Quantification of Plasmodium-host protein. Malar J. 2015 Feb 21;14:88.
Adams NM, Olmsted IR, Haselton FR, Bornhop DJ, Wright DW. The effect of hybridization-induced secondary structure alterations on RNA detection using backscattering interferometry. Nucleic Acids Res. 2013 May;41(9)
Baksh MM, Kussrow AK, Mileni M, Finn MG, Bornhop DJ. Label-free quantification of membrane-ligand interactions using backscattering interferometry. Nat Biotechnol. 2011 Apr;29(4):357-60.
Bornhop DJ, Latham JC, Kussrow A, Markov DA, Jones RD, Sørensen HS. Free-solution, label-free molecular interactions studied by back-scattering interferometry. Science. 2007 Sep 21;317(5845):1732-6.