Dual-Label Flow Cytometry for Circulating Tumor Cell Detection
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Solution Overview
Problem
Current methods for detecting circulating tumor cells in blood samples face challenges due to their rarity and difficulty in distinguishing them from healthy cells, leading to limitations in sensitivity and specificity, resulting in mischaracterization of healthy cells as cancerous and missed cancer cells.
Innovation Solution
A method utilizing flow cytometry with dual labeling of cytokeratin markers (CK-Red and CK-Green) and their respective fluorochromes, FITC and Alexa Fluor 647, to enhance detection sensitivity and specificity by plotting fluorescence density, allowing for the identification of tumor cells amidst a background of white blood cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If single labeling of cytokeratin markers is used, then the detection method is simpler, but the sensitivity and specificity are insufficient leading to mischaracterization of healthy cells
Solution Approach 1:
The patent divides the detection system into two independent labeling channels: a first labeling channel that labels cytokeratin markers on tumor cells with a first fluorochrome, and a second labeling channel that labels the same markers with a second fluorochrome. This segmentation allows independent optimization of each labeling channel and enables dual-color fluorescence detection, significantly improving sensitivity and specificity while maintaining manageable complexity through modular design
Solution Approach 2:
The patent transitions from single-color fluorescence detection to dual-color fluorescence detection by introducing a second fluorochrome with different emission characteristics. This dimensional expansion in the fluorescence spectrum allows discrimination between tumor cells and healthy cells based on their distinct labeling patterns, achieving superior measurement precision without excessive complexity increase
2Productivity
If flow cytometry is used to detect rare circulating tumor cells, then rapid analysis is enabled, but the rarity and similarity of CTCs to healthy cells make detection difficult
Solution Approach 1:
The patent applies different labeling strategies to different cell populations: tumor cells are labeled with both first and second fluorochromes (double-positive), while healthy cells are labeled with only one fluorochrome (single-positive) or neither. This local differentiation in labeling quality enables flow cytometry to rapidly distinguish CTCs from healthy cells based on their unique fluorescence signatures, maintaining both speed and accuracy
Solution Approach 2:
The patent utilizes different fluorochromes with distinct emission colors (e.g., cyan and red) to label tumor cells and healthy cells differently. The flow cytometer detects these color differences through fluorescence emission at different wavelengths, enabling rapid and accurate identification of rare tumor cells among abundant healthy cells based on their characteristic fluorescence color patterns
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 discriminates circulating tumor cells from non-rare cells, reducing false positives and enabling accurate detection even at low concentrations, as demonstrated by the ability to identify one tumor cell among millions of white blood cells without registering false positives.
Implementation Method 1
Each sample component is illuminated by a light source, such as a laser, and light scattered by each sample component is detected and analyzed
Data Source
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AI summary
The present disclosure provides cytometric methods for the detection of rare target cells in a sample. In certain aspects, the methods and compositions may facilitate the detection of rare target cells, such as circulating tumor cells (CTCs), in a biological sample such as blood. Aspects of the methods include contacting the sample with first and second binding members that specifically bind to a marker of the rare target cell, and cytometrically assaying the sample for the presence of cells comprising bound first and second binding members to detect the rare target cell in the sample. Also provided are systems, compositions, and kits for practicing the subject methods.