Droplet-based microfluidics has been demonstrated to offer the advantage of high precision control, high throughput, and material savings. Traditional fabrication methods of droplet generation involve soft lithography, molding, etching, and embossing process, relying on expensive equipment, tedious operations, and even requiring a cleanroom fabrication environment. Recently, 3D printing with the characteristics of low cost, easy reprinting, and well-achieved microstructure in three dimensions has been suggested as a promising technology to improve the fabrication of microfluidics. In this study, we combined 3D printing technology and microfluidics to design a microfluidic device that enables the continuous generation of droplets, which can be utilized to encapsulate single particles and cells. The digital model of the microfluidic device was designed and edited by software, and then uploaded to a stereolithography 3D printer with a resolution of 10 μm for printing. To verify the feasibility of the device to generate droplets, the mineral oil and water were used as the continuous phase and the dispersed phase, respectively. The diameters of droplets ranging from about 70 μm to 240 μm and the product rate about 1500/min can be achieved. The result of encapsulation probability of microspheres is around 55% with that of the single-microspheres about 30%, which verifies the ability of droplet device for encapsulating single particles. The droplet microfluidics is applied for cell imaging to monitor the cell viability for a long time. The result presents the viability changes from the living state to death of MDA-MB-231 breast cancer cells.
In this manuscript, we aim to develop the dynamic light scattering imaging (DLSI) method to investigate the difference between triple negative breast cancer (TNBC) and human epidermal growth factor receptor-2 (HER-2) positive breast cancer. The experimental device with the capability to obtain time-series light scattering images was well designed and built. The breast cancer cell lines of MDA-MB-231 and HER-2 enriched SKBR3 were prepared and used for experiments. The autocorrelation functions of the light intensity fluctuation were calculated to characterize both types of breast cancer cells. The dynamic light scattering images were further analyzed to establish a DLSI-based approach for automatic classification of the two types of cells. The results show that the proposed DLSI-based model achieved better classification performance compared to the conventional static light scattering-based model.
In this manuscript, we develop a 3D-printing based microfluidic device for light scattering imaging of single cells. A rapid fabrication method to make microfluidic device that enables 3D-hydrodynamic focusing by utilizing 3D printing technique is proposed. The focusing effect of the microfluidic cytometer was measured and shows the ability to confine the cells to flow near the center stream along the channel. Also, the standard beads with 9.51 μm in diameter were used to test the reliability of the device. The collected light scattering images are in good agreement with simulation results. We suggest that the 3D-printing based light scattering microfluidic device is in principle applicable for fast, label-free detection of single cells.
Two-dimensional (2D) light scattering microscopy is one of the label-free imaging technologies that allows to image the particles out of focal plane. In this manuscript, we try to develop a volume scanning-based 2D light scattering microscopy that aims to fast determine the 3D location of single particles by taking the advantage of defocusing strategy, which is expected to improve the efficiency of common refocusing-based localization methods. To demonstrate the principle of our volume scanning-based 2D light scattering microscopy, the standard beads are used to perform the experiments. The vertical position of individual beads can be determined by measuring the area of the scattering patterns. The volume scanning-based 2D light scattering microscopy is proposed to provide a fast and label-free method for 3D localization of single particles.
Microfluidic cytometry has led to great progress in the field of single cell analysis. Here a light scattering microfluidic cytometer with dual-channel three-dimensional (3D) hydrodynamic focusing is developed, which potentially enables single cell or particle measurements with high-throughput. The light sheet illumination is introduced to provide a uniform excitation. Two dimensional (2D) light scattering patterns of label-free single cells or particles are imaged by a CMOS sensor via an objective lens (10x). The focusing effect of our dual-channel 3D hydrodynamic focusing unit is visualized. Simultaneous measurements of standard beads with different concentrations and sizes are performed. Our results demonstrate that the light scattering microfluidic cytometer with dual-channel 3D hydrodynamic focusing is promising for parallel, label free analysis of various cells with an enhanced throughput.
The detection of senescent cells becomes increasing important for tumor therapy and drug screening. Here a light sheet microfluidic cytometer with a disposable hydrodynamic focusing unit is developed for two dimensional (2D) light scattering measurements of single cells. The mixed polystyrene microspheres of 3.87 and 2.0 μm in diameter are successfully differentiated by our 2D light scattering microfluidic cytometer. The application of the 2D light scattering microfluidic cytometry for the label-free analysis of senescent cells without any labeling or staining is demonstrated by measurements of H2O2-treated U87 cells. Our light sheet-based 2D light scattering microfluidic cytometer is easy to assemble with a disposable hydrodynamic unit, which may find wild applications in clinics for label-free cell classification.
Two-dimensional (2D) light scattering cytometry has been demonstrated as an effective label-free technology for cell analysis. Here we develop the light-sheet illumination in 2D light scattering static cytometry. In our cytometer, a cylindrical lens is used to form the light-sheet for better excitation of the static cells under an inverted microscope. The thickness of the light-sheet measured in fluorescent solution is about 13 μm. Two-dimensional light scattering patterns of standard microspheres and yeast cells are obtained by using a complementary metal oxide semiconductor (CMOS) detector via a low numerical aperture (NA 0.4) optical objective. The experimental patterns characterized with fringe structures agree well with Mie theory simulated ones. Our results suggest that the light-sheet illumination is an effective excitation method for 2D light scattering label-free cytometry.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.