Design of a microfluidic platform for real-time enumeration and retrieval of low concentration of cells

2022-9
Şahin, Buket
Spiking experiments are essential to characterize the performance of devices developed for rare cell recovery. However, it is challenging to spike tumor cells at very low concentrations in a standard laboratory environment with conventional methods like serial dilution, in which the variation becomes quite high. Other platforms for single-cell picking are extremely high cost and not available in standard laboratories. We propose a low-cost, repeatable, and robust microfluidic system to spike a very low number of cells (1-100) with high accuracy, without any sample loss and dead volume. The platform included a PDMS microfluidic chip and a flexible hydraulic reservoir (FHR) connected to the outlet reservoir, providing zero dead volume. To characterize the system, fluorescently stained cells were passed through the channel and collected directly in the pipette tip connected to FHR. Cells passing through the microchannel were monitored under a microscope and counted in real-time. Then, the collected cells were transferred to a well plate and counted for comparison. The average collected cell count was 9.2±2.4, 49.4±5.9 and 98.5±6.2 for targeted 10, 50, and 100 MCF7 cells, respectively. The counting accuracy was demonstrated by linear regression between real-time versus retrieved cell counts with an R2 of 0.9964. The microfluidic platform does not affect cell viability. The proposed system provides low-cost and robust technique for accurate spiking of low number of cells for analytical performance characterization of rare cell isolation platforms or any other analytical study requiring few cells.

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Citation Formats
B. Şahin, “Design of a microfluidic platform for real-time enumeration and retrieval of low concentration of cells,” M.S. - Master of Science, Middle East Technical University, 2022.