Dielectric Spectroscopy for Viable Cell Volume
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Solution Overview
Problem
Existing methods for predicting viable biomass in cell cultures, such as trypan blue dye exclusion and capacitance-based techniques, face inaccuracies when cell viability changes, leading to divergences in measured values.
Innovation Solution
Dielectric spectroscopy using a frequency-swept electrical measuring device to measure capacitance and relative permittivity across various frequencies, allowing for the estimation of viable cell volume by correlating capacitance values with trypan blue dye exclusion results, and correcting for divergences using integral ratios of the beta-dispersion curve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If capacitance-based techniques are used to predict viable biomass, then measurement speed is improved, but measurement precision deteriorates when cell viability changes
Solution Approach 1:
The patent applies parameter changes by measuring electrical properties across multiple frequencies rather than a single frequency. The system sweeps through a frequency range to capture the beta-dispersion curve, extracting multiple parameters (capacitance at different frequencies, curve shape characteristics) that together provide accurate viable biomass prediction even when cell viability changes, resolving the contradiction between speed and precision.
Solution Approach 2:
The patent transitions from single-frequency measurement to multi-frequency spectral measurement, adding the frequency dimension to the measurement space. By analyzing the entire beta-dispersion curve across frequencies rather than a single point, the system maintains measurement speed while significantly improving precision through the additional dimensional information.
2Device complexity
If single-frequency capacitance measurement is used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent implements multi-functionality by designing a frequency-swept measuring device that can operate across multiple frequencies while maintaining a relatively simple overall structure. The same basic measuring apparatus performs multiple measurement functions at different frequencies, extracting comprehensive information about cell properties without requiring complex specialized equipment for each frequency point.
3Measurement precision
If trypan blue dye exclusion method is used to measure viable cell volume, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent replaces the mechanical/manual trypan blue staining and counting process with an electrical measurement system. Instead of manually mixing dye and counting cells under a microscope, the system uses electrical field interactions to measure viable cell volume, achieving comparable or superior precision while dramatically reducing measurement time and eliminating manual intervention.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate measurement of cell viability throughout the cell culture life cycle, allowing for precise control of feeding schemes and reducing product impurities by correlating electrical property data with biological properties, improving the prediction of viable biomass.
Implementation Method 1
measuring capacitance and relative permittivity of the population of cells by applying electrical signals across various frequencies
Implementation Method 2
measuring capacitance and relative permittivity of the population of cells
Implementation Method 3
The beta-dispersion mechanism is due to Maxwell-Wagner polarization (interfacial polarization) at the external and internal interfaces of the phospholipid membrane
Data Source
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AI summary
Methods and apparatus are disclosed for correcting measurements us¬ ing calibration by applying a frequency-varying signal with a measur¬ ing device for performing dielectric spectroscopy (e.g., a permittivi¬ ty probe) to a population of living cells (e.g., contained in a bioreac- tor) and correcting measurement divergences using data acquired us¬ ing an alternate analytical method (e.g., trypan blue exclusion, hemo- cytometry or fluorescent flow cytometry). In one example, a method comprises receiving electrical property data for a first population of cells, the data obtained by applying a first frequency-varying signal to the population with the measuring device, receiving biological prop¬ erty data obtained using the alternate analytical technique, generat¬ ing at least one value representative of the frequency dependence of the electrical property data, and determining a relationship between the biological property data and the representative value. In some ex¬ amples, measurements of apoptosis are predicted using the electrical property data.