Methods and systems of detecting exocytosis of a target molecule from a population of cells
Inventors
Messerli, Mark Alan • Heart, Emma • Xu, Munan • Messerli, Shanta Menon
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-9739734-B2
Publication Date
2017-08-22
Expiration Date
Abstract
A method of detecting exocytosis of a target molecule from a population of cells derived from a human subject, includes applying first and second electrical signals, each having a respective frequency, across the population of cells. Each of the first and second electrical signals being either an alternating current or an alternating voltage. The method includes measuring a first voltage change if the first electrical signal is an alternating current or measuring a first current change if the first electrical signal is an alternating voltage, and measuring a second voltage change if the second electrical signal is an alternating current or measuring a second current change if the second electrical signal is an alternating voltage. The method includes determining an electrical impedance of the population of cells, a change in that impedance indicating an amount of the target molecule released from the population of cells.
Core Innovation
The disclosure relates to detecting and measuring exocytosis of a target molecule comprising insulin, glucagon, somatostatin, or any combination thereof from a population of cells that is known or suspected to produce the target molecule, where the population is derived from a human subject. An electrical impedance of the population of cells is determined at a first frequency and at a second frequency based on electrical signals applied across the population of cells.
A first electrical signal with a first frequency is applied across the population of cells, where the first electrical signal is either an alternating current or an alternating voltage. A second electrical signal with a second frequency is applied across the population of cells, where the second electrical signal is either an alternating current or an alternating voltage. Voltage or current changes are measured at each frequency corresponding to the electrical signal type.
Changes in the electrical impedances of the population of cells indicate an amount of the target molecule released from the population of cells. The disclosed approach supports impedance modeling using an equivalent electric circuit with passive elements, including a capacitor representing summed plasma membrane capacitances, and further supports decomposing measured signals into in-phase and out-of-phase components to separate resistor and capacitor contributions and determine capacitor impedance.
Claims Coverage
The independent claim is directed to a method for detecting and measuring exocytosis of a target molecule from a human-derived population of cells by applying two electrical signals at different frequencies and using impedance changes to indicate an amount of target molecule released. Dependent claims refine impedance determination via equivalent electric-circuit modeling and in-phase/out-of-phase component separation, and further narrow signal application timing and sample/agent context.
Dual-frequency electrical impedance detection of exocytosis
Applying a first electrical signal with a first frequency across the population of cells (alternating current or alternating voltage), applying a second electrical signal with a second frequency across the population of cells (alternating current or alternating voltage), measuring a first voltage change or a first current change at the first frequency, measuring a second voltage change or a second current change at the second frequency, and determining a change in an electrical impedance of the population of cells at each of the first frequency and the second frequency, wherein the changes in the electrical impedances indicate an amount of the target molecule released from the population of cells.
Equivalent electric-circuit modeling with passive elements and capacitor representing summed plasma membrane capacitances
Determining changes in electrical impedance of a population of cells by fitting measured voltage or current changes to an equivalent electric-circuit model that uses passive elements including a capacitor representing the sum of plasma membrane capacitances of all cells in the population, where the resulting capacitor impedance change indicates the amount of a target molecule released.
Capacitor impedance from out-of-phase component
Determining the capacitor’s impedance by decomposing each measured voltage or current change into in-phase and out-of-phase components and calculating the impedance from the out-of-phase components.
Passive-element impedance extraction from in-phase and out-of-phase voltage components
Determining electrical impedance of a population of cells by decomposing the measured voltage change into an in-phase component and an out-of-phase component relative to the applied current to derive impedances of passive circuit elements modeling the cells.
Simultaneous application of dual-frequency signals
Applying a first and a second electrical signal simultaneously.
Agent-modulated insulin exocytosis context
Contacting a population of cells with an agent that is identified for or being assessed for modulating insulin exocytosis.
Overall, the claim set centers on impedance-based detection of target molecule exocytosis using two-frequency electrical excitation, with refinements that model cells using an equivalent electric circuit (including a capacitor representing summed plasma membrane capacitances) and/or compute capacitor impedance using in-phase and out-of-phase signal decomposition, plus narrowing features covering simultaneous dual-frequency application and use of an agent modulating insulin exocytosis.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?