Size‐resolved counting of circulating tumor cells on pinched flow‐based microfluidic cytometry

Abstract

Precise cell detecting and counting is meaningful in circulating tumor cells (CTCs) analysis. In this work, a simple cyclic olefin copolymer (COC) microflow cytometer device was developed for size‐resolved CTCs counting. The proposed device is constructed by a counting channel and a pinched injection unit having three channels. Through injection flow rate control, microspheres/cells can be focused into the centerline of the counting channel. Polystyrene microspheres of 3, 9, 15, and 20 µm were used for the microspheres focusing characterization. After coupling to laser‐induced fluorescence detection technique, the proposed device was used for polystyrene microspheres counting and sizing. A count accuracy up to 97.6% was obtained for microspheres. Moreover, the proposed microflow cytometer was applied to CTCs detecting and counting. To mimic blood sample containing CTCs and CTCs mixture with different subtypes, an MDA‐MB‐231 (human breast cell line) spiked red blood cells sample and a mixture of MDA‐MB‐231 and MCF‐7 (human breast cell line) sample were prepared, respectively, and then analyzed by the developed pinched flow‐based microfluidic cytometry. The simple fabricated and easy operating COC microflow cytometer exhibits the potential in the point‐of‐care clinical application.

Breaking the clean room barrier: exploring low-cost alternatives for microfluidic devices

“…COC possesses numerous advantageous properties, including low water absorption, excellent electrical insulation, long-term surface treatment stability, and resistance to a broad range of acids and solvents ( Shakeri et al, 2022b ; Guan et al, 2022 ). It is an ideal material for use in diverse applications, such as biological, membrane, and semiconductor fields ( Etxeberria et al, 2022 ; Xia et al, 2023 ). COC is remarkable for its stiffness, optical clarity, and heat deflection temperature, which varies between 70°C and 170°C, depending on the COC grade ( Bruijns et al, 2019 ; Agha et al, 2022 ).…”

Particle Counting Methods Based on Microfluidic Devices

“…The developed method reduces the limit of detection (LOD) to 10 enzyme-labeled exosome complexes per microliter (10 −17 M), allowing for the discovery of cancer exosome biomarkers for clinical diagnosis and potentially enabling early cancer detection [ 36 ]. Another study by Xia et al [ 37 ] created a cyclic olefin copolymer (COC) microchip with a simple cross-channel layout that, once coupled to a laser-induced fluorescence detector, resulted in a microfluidic cytometer with a counting accuracy of 97.6%. This improved accuracy allowed for more precise counting of lower concentrations of large microspheres.…”