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.

Suggestions

Assessment of effects of multi drug resistance on dielectric properties of K562 leukemic cells using electrorotation
Bahrieh, Garsha; Erdem, Murat; Ozgur, Ebru; Gündüz, Ufuk; Külah, Haluk (2014-01-01)
In this study, dielectric characterization of multidrug resistant (MDR) K562 human leukemia cells was carried out using a MEMS based electrorotation (ER) device with 3D electrodes. P-glycoprotein (P-gp) dependent MDR causes variation in cell dielectric properties (cell interior conductivity (sigma(i)), membrane capacitance (C-m) and total effective membrane conductance (G(m)*)) due to overexpression of P-gp, which modulates the activity of membrane-bound Cl- channels. Different cell populations resistant to...
Dielectric Analysis of Changes in Electric Properties of Doxorubicin Resistant K562 Leukemic Cells Through Electrorotation with 3 D Electrodes
Garsha, Bahrieh; Erdem, Murat; Özgür, Ebru; Gündüz, Ufuk; Külah, Haluk (2013-10-31)
In this study, dielectric characterization of multidrug resistant (MDR) K562 human leukemia cells was carried out using a MEMS-based electrorotation (ER) device with 3D electrodes. Different cell populations were utilized, which were resistant to 0.1, 0.3, and 0.5 μM doxorubicin. The ER devices with 3D quadruple electrodes (30 urn in height) were used, in order to eliminate the fringing field effect on the rotation of cells. Signals in phase quadrature were applied to the polynomial electrodes, to induce th...
Simulation of an efficient silicon heterostructure solar cell concept featuring molybdenum oxide carrier-selective contact
MEHMOOD, Haris; NASSER, Hisham; Tauqeer, Tauseef; HUSSAIN, Shahzad; Ozkol, Engin; Turan, Raşit (2018-03-25)
Transition metal oxides/silicon heterocontact solar cells are the subject of intense research efforts owing to their simpler processing steps and reduced parasitic absorption as compared with the traditional silicon heterostructure counterparts. Recently, molybdenum oxide (MoOx, x<3) has emerged as an integral transition metal oxide for crystalline silicon (cSi)-based solar cell based on carrier-selective contacts (CSCs). In this paper, we physically modelled the CSC-based cSi solar cell featuring MoOx/intr...
Preparation and characterization of sulfonated polysulfone/titanium dioxide composite membranes for proton exchange membrane fuel cells
Devrim, Yiser; Erkan, Serdar; BAÇ, NURCAN; Eroğlu, İnci (2009-05-01)
In the present study, sulfonated polysulfone (sPS)/titanium dioxide (TiO2) composite membranes for use in proton exchange membrane fuel cells (PEMFCs) were investigated. Polysulfone (PS) was sulfonated with trimethylsilyl chlorosulfonate in 1,2 dichloroethane at ambient temperatures. It was shown that the degree of sulfonation is increased with the molar ratio of the sulfonating agent to PS repeat unit. The degree of sulfonation was determined by elemental analysis and H-1 NMR was performed to verify the su...
INVESTIGATION OF THE PERMEABILITY OF THE CELL MEMBRANE FOR DIFFERENT CRYOPROTECTANT AGENTS IN A CONTINUOUS THERMO-FLUIDIC MICRO-CHANNEL SYSTEM
Hatiboğlu, Anıl; Külah, Haluk; Önel, Selis; Department of Micro and Nanotechnology (2021-9-13)
Modeling cell membrane permeability in different solutions is a critical requirement in controlling the response of cells during preconcentration processes in biotechnological applications, such as drug delivery, fluorescence imaging, and cryopreservation . Current multi-step methods employed in loading cells with high concentrations of cryoprotectant agents (CPAs) prior to cryopreservation for long term storage affect cell viability as a result of extended exposure times associated with these methods. One ...
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.