Reverse-Flow Magnetic Bead Labeling for Rare Cell Separation
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Solution Overview
Problem
Existing methods for separating rare cells from blood, such as circulating tumor cells (CTCs), face challenges with high false-positive and false-negative rates due to the capture of white blood cells, which are of similar size and deformability, leading to inefficient labeling and separation.
Innovation Solution
A method and apparatus for magnetically labeling particles captured by a filter, involving the use of magnetic beads, where a suspension containing magnetic beads is passed through the filter in a reverse direction to enhance contact with both surfaces, increasing labeling efficiency and separation precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a filter is used to capture rare cells from blood, then rare cells can be separated, but white blood cells are also captured leading to false positives
Solution Approach 1:
The filtering process is segmented into two distinct stages: first capturing rare cells along with white blood cells, then performing a second filtering pass to remove white blood cells. This segmentation allows the system to achieve both high rare cell capture and high purity by dividing the separation task into manageable steps.
Solution Approach 2:
White blood cells are removed in a preliminary action before final rare cell analysis. The system performs an initial filtration to capture target cells, then executes a secondary filtration step to eliminate white blood cells that would cause false positives, ensuring high detection accuracy in the final analysis.
2Productivity
If magnetic beads are used to label particles, then separation can be performed, but labeling efficiency is low when particles are captured on filter surface
Solution Approach 1:
Instead of passing the magnetic bead suspension through the filter in the same direction as sample flow, the system reverses the flow direction. The suspension is introduced from the outlet side and flows backward through the filter, allowing magnetic beads to contact captured particles from the opposite direction, which significantly improves labeling efficiency.
Solution Approach 2:
The system adds a dimensional aspect to the labeling process by introducing the magnetic bead suspension from the outlet side rather than the inlet side. This dimensional change in flow direction creates a counter-current labeling mechanism that enhances contact between magnetic beads and captured particles on the filter surface.
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
The method effectively labels particles, particularly white blood cells, allowing for precise separation of rare cells by magnetically separating labeled white blood cells, reducing false positives and negatives, and enhancing the overall accuracy of rare cell analysis.
Implementation Method 1
magnetic separation is a method that depends on proteins expressed in cells that are to be separated
Data Source
AI summary
The present disclosure relates to a method for labeling particles with magnetic particles and an apparatus for labeling particles with magnetic particles.