Design and Simulation of a Circulating Tumor Cell Detector

Abstract

Recent advances in magnetic cell selection have enhanced the possibility of isolating cells of interest. The detection of fetal cells in maternal blood, circulating stem cells and circulating tumor cells will soon be a technology that can be transferred to point-of-care (POC) diagnosis. As a component of a POC portable rare cell analyzer a three-stage magnetic trap for magnetically labeled rare cells was designed and tested. The trap design consists of a flow channel with three bends and a permanent magnet positioned at the outer curve of each bend. Findings are reported on the computational fluid dynamic analysis of the design, testing with model commercial magnetic beads used in cell labeling, and testing with immunomagnetically labeled cultured melanoma cells in the presence of whole blood. The computational results provide cell flow data along stream lines as a function of position in the trap. The measurements of field profiles of the magnets were used to determine forces applied as a function of position in the trap. Testing with 3.27 μm diameter standard magnetic beads (Seragen) indicated that at least 99.998% of these strongly magnetic particles are captured within the trap, most in the first stage. The laboratory test used Bursa Lymphoma of Chicken (Gallus gallus) as target cell and the labeling and separation test proved the device is able to separate the target cell. The test proved the static mixer has the same performance as shaker table used in laboratory. Meanwhile, the device proved to be effective in cell labeling and separation.