Microfluidic Isoelectric Focusing Device for Precise Protein Zone Extraction
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Solution Overview
Problem
Existing microfluidic electrophoretic devices face limitations in achieving high precision for the selection and extraction of capillary isoelectric focusing (cIEF) component zones due to one-directional mobilization flow, fixed mobilization speed, and inability to visualize and detect zone-width distortions in real-time, leading to cross-contamination and inefficient peak collection.
Innovation Solution
A micro-scale electrophoresis device (IMED) with a coplanar cross-channel configuration, enabling time-independent movement of selected analyte zones using gravity or microfluidic delivery, combined with real-time whole-column imaging detection for precise alignment and extraction of specific peaks into an extraction channel, allowing for high-resolution protein separation and selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional vial collection or membrane collection is used at the exit of the separation column, then fraction collection can be achieved, but cross-contamination occurs due to extremely narrow peak width and extremely small amount of eluant
Solution Approach 1:
The invention transitions from point-detection collection at the outlet to whole-column imaging detection, adding a spatial dimension to the collection process. By imaging the entire separation channel and collecting fractions based on visualized peak positions, the system achieves precise fraction collection without cross-contamination, resolving the contradiction between collection precision and contamination risk
Solution Approach 2:
The invention implements real-time feedback through whole-column imaging detection, allowing the system to monitor peak positions and widths continuously. This feedback enables dynamic adjustment of collection timing and parameters, ensuring precise fraction collection while preventing cross-contamination by stopping collection when peaks begin to broaden or overlap
2Quantity of substance
If exact timing is used for precise fractionation in CE, then small volumes of individual fractions can be collected, but timing precision is difficult to achieve due to fixed mobilization speed and one-directional flow
Solution Approach 1:
The invention makes the collection system dynamic by enabling bidirectional mobilization of analyte zones. Instead of relying on fixed one-directional flow, the system can move zones forward and backward to achieve precise alignment with the collection point, dramatically improving timing precision and fraction volume control
Solution Approach 2:
The invention replaces mechanical timing-based collection with optical imaging-based collection. By using whole-column imaging to detect peak positions and triggering collection based on visualized peak arrival, the system eliminates timing errors associated with fixed mobilization speeds and achieves precise fractionation
3Measurement precision
If cIEF is used to separate amphoteric substances, then high-resolution separation is achieved with narrow stationary zones, but the ability to select and extract specific zones precisely is limited
Solution Approach 1:
The invention introduces whole-column imaging detection as an intermediary between separation and extraction. The imaging system visualizes the positions and widths of focused zones, providing real-time information that guides precise extraction. This intermediary enables accurate selection and extraction of specific cIEF zones while maintaining their narrow focus
Solution Approach 2:
The invention creates a visual copy of the separation channel through imaging, allowing operators to see the actual positions and shapes of analyte zones. This optical copy enables precise identification and selection of target zones for extraction, improving extraction precision while maintaining the high-resolution separation achieved by cIEF
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 precise and automated extraction of proteins with minimal peak broadening, increasing the analytical success of subsequent techniques like mass spectrometry by allowing for the selection and collection of specific peaks while maintaining focus, thereby overcoming previous limitations in precision and contamination.
Implementation Method 1
separating and focusing components of the analyte mixture into separated zones in the separation channel using capillary isoelectric focusing
Implementation Method 2
Across the separation capillary or channel, voltage is applied and a pH gradient is created by carrier ampholytes
Implementation Method 3
causing selected zones of analytes separated by capillary isoelectric focusing to move to said intersection of the separation and extraction channels
Implementation Method 4
optical whole column imaging detection apparatus for monitoring the isoelectric focusing process and observing the position of the separated zones of analyte
Implementation Method 5
means for applying an extraction force to direct a single zone containing a selected analyte into and then out of extraction channel
Data Source
AI summary
An apparatus and method are disclosed for the precise selection and extraction of a selected analyte in a focused zone produced by isoelectric focusing performed in micro-channels. A cross-channel microfluidic device comprises a sample mixture introduction and separation channel and an extraction channel, which are in fluid communication with each other at a point of intersection. Means are provided for selectively moving the pattern of separated zones following cIEF to the intersection point, and means are provided for applying an extraction pressure to direct a single zone containing a selected analyte into and then out of the extraction channel for collection.