Label-free quantification of cell surface membrane protein binding kinetics in biological systems
AssigneeArizona Board of Regents on behalf of Arizona State University
InventorsShaopeng Wang, Fenni Zhang
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Abstract
Disclosed herein is a system and method for quantitative detection and analysis of molecular binding kinetics of a substance with surface membrane proteins of a biological object, such as a live cell, based on detecting and tracking membrane fluctuation amplitude changes caused by membrane displacement associated with the binding of the substance with the surface membrane proteins. The molecular binding kinetics can be detected with high precision in real time from an optical image of the biological object with a differential detection method.
Claims20
A system for quantitative detection and analysis of mechanics and molecular binding kinetics of a substance with surface membrane proteins of a biological object, the system comprising:
- a) a housing configured to hold the biological object;
- b) a microfluidic injector configured for fluid communication with the housing to introduce the substance to the biological object;
- c) an optical imaging apparatus configured to capture a time sequence of optical images of the biological object;
- and
- d) a processor configured to receive the time sequence of optical images from the optical imaging apparatus and to track membrane fluctuation amplitude changes of the biological object associated with binding of the substance with the surface membrane proteins from the time sequence of optical images,
- wherein the processor comprises an image processing algorithm that:
- filters a measured membrane displacement at a frequency of about 1 Hz or more for membrane fluctuation tracking;
- calculates a first membrane fluctuation amplitude with a root mean square displacement (RMSD) of about a 150 second membrane fluctuation signal;
- and
- determines an effective local spring constant to produce a cell mechanics determination for the biological object;
- and,
- calculates an average over a whole membrane displacement;
- filters the whole membrane displacement at a frequency of about 1 Hz or more for membrane fluctuation tracking;
- and
- calculates a second membrane fluctuation amplitude with a RMSD of about every 1 second to determine binding curves to produce a binding kinetics determination for the biological object.
A method for quantitative detection and analysis of mechanics and molecular binding kinetics of a substance with surface membrane proteins of a biological object, the method comprising:
- a) introducing the substance to interact with the biological object;
- b) capturing a time sequence of optical images of the biological object;
- c) tracking membrane fluctuation amplitude changes of the biological object associated with binding of the substance with the surface membrane proteins;
- and
- d) producing a cell mechanics determination for the biological object by filters a measured membrane displacement at a frequency of about 1 Hz or more for membrane fluctuation tracking, calculating a first membrane fluctuation amplitude with a root mean square displacement (RMSD) of about a 150 second membrane fluctuation signal, and determining an effective local spring constant;
- and
- e) producing a binding kinetics determination for the biological object by calculating an average over a whole membrane displacement, filtering the whole membrane displacement at a frequency of about 1 Hz or more for membrane fluctuation tracking, and calculating a second membrane fluctuation amplitude with a root mean square displacement (RMSD) of about every 1 second to determine binding curves.
Dependencies are inferred from the claim text.