Bioreactor Sampling Control for Stable Microenvironment Analysis
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Solution Overview
Problem
Current bioreactor technologies face challenges in non-perturbatively sampling and maintaining the microenvironment of small volume-limited bioreactors, leading to significant volume changes and metabolic disruptions during sample removal, which affect the accuracy of metabolic and gene expression analysis.
Innovation Solution
A system with controlled input and output pumps and a controller manages bioreactor parameters to maintain a stable microenvironment during sample accumulation, storage, and withdrawal, ensuring minimal perturbation by adjusting inflow and outflow rates and gas exchange to mimic chemostatic conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If samples are removed from small bioreactors for analysis, then sample volume is obtained for metabolic and gene expression analysis, but the bioreactor volume changes significantly causing metabolic disruptions and microenvironment perturbations
Solution Approach 1:
The system accumulates sample volume in advance within the bioreactor before analysis is needed. The controller monitors bioreactor volume and selectively accumulates sample when volume is sufficient, then removes the accumulated sample for analysis. This preliminary accumulation allows obtaining adequate sample volume without causing significant volume changes or metabolic disruptions during the actual sampling event, as the removal occurs in a single step rather than repeatedly throughout the experiment.
2Quantity of substance
If multiple samples are removed sequentially from small bioreactors, then sufficient sample volume is obtained for comprehensive analysis, but the frequency of sampling causes cumulative metabolic disruptions
Solution Approach 1:
The system accumulates multiple samples sequentially within the bioreactor over time, storing them in a reserved volume before analysis. The controller tracks accumulated sample volume and only removes samples when sufficient volume has been accumulated. This approach allows obtaining comprehensive sample volume for multiple analyses while maintaining metabolic condition consistency, as all samples are collected under the same stable microenvironment conditions rather than through repeated disruptive sampling events.
3Stability of the object's composition
If bioreactor volume is maintained constant during sampling, then microenvironment stability is preserved, but sample accumulation time increases significantly
Solution Approach 1:
The system dynamically adjusts the bioreactor working volume based on real-time conditions. The controller monitors bioreactor volume and selectively increases the working volume to accommodate accumulated sample when sufficient sample has been collected, then restores the original volume after sample removal. This dynamic volume adjustment allows faster sample accumulation compared to maintaining constant volume, while still preserving microenvironment stability through controlled, selective volume changes rather than frequent perturbations.
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 and non-perturbative sampling from small bioreactors, maintaining consistent metabolic conditions, allowing for rapid and efficient analysis of multiple samples without disrupting the bioreactor environment.
Implementation Method 1
an input pump coupled to the input tube and configured to operably deliver, by the input tube, the nutrient-laden media at the inflow rate
Implementation Method 2
an output pump coupled to the output tube and configured to operably withdraw, by the output tube, the sample at the outflow rate
Implementation Method 3
the controller is coupled to the input pump and the output pump and configured to operate the input pump and the output pump to regulate the inflow rate and the outflow rate, respectively, such that the chemical and physical microenvironmental conditions within the bioreactor are maintained in a stable state
Data Source
AI summary
A non-perturbative sampling system includes a bioreactor comprising a chamber containing media with cells; an input tube for delivering nutrient-laden media to the chamber; and an output tube for withdrawing a sample from the chamber; an input pump configured to deliver the nutrient-laden media at an inflow rate; an output pump configured to withdraw the sample at an outflow rate; and a controller configured to operate the input and output pumps to regulate the inflow and outflow rates, respectively, such that the bioreactor is a variable-volume bioreactor in which an instantaneous volume of media either varies continuously with time or is held constant, and operable in sample accumulation phase, sample storage phase, sample withdrawal phase, or volume restoration phase, to maintain the quantity of nutrients per cell within the media in the chamber unchanged. The sample withdrawal phase either follows the sample accumulation phase or precedes the volume restoration phase.