Inexpensive microfluidic device enables the imaging of cells one-by-one

The ability to classify individual cells within a large population based on microscopy images has wide-ranging applications in disease diagnosis and basic research. Patel et al. created a method that could be used to automate high-resolution images of cells in a one-by-one manner.

Using a device the size of a microscope slide, the researchers were able to focus the cells in a single-file arrangement close to the bottom wall of the device, so that a high-magnification objective could be used to image the cells. This is particularly important for high-resolution images of cells as high-magnification microscope objectives have small field-of-view and depth-of-field.

“We were able to image a large number of cells one-by-one by manipulating the cells passively just by controlling the flow rates of liquids fed into this simple device,” said author Supreet Bahga.

By adjusting the fluid flow within their device, the researchers were able to move the cells in a single line within a single plane, so that the microscope objective could be positioned at a particular location and image the cells as they flow through the detection region in a single file.

While the researchers have used bright-field imaging to image the red blood cells in the current work, they reckon that the same approach can be used for various other microscopy techniques. The simple device design and the ability to manufacture it cheaply would make it particularly beneficial when automating high-resolution imaging of cells, as the device must be disposed of after one-time use to avoid contamination in such applications.

Source: “An inexpensive microfluidic device for three-dimensional hydrodynamic focusing in imaging flow cytometry,” by Yogesh M. Patel, Sanidhya Jain, Abhishek Kumar Singh, Kedar Khare, Sarita Ahlawat, and Supreet Singh Bahga, Biomicrofluidics (2020). The article can be accessed at https://doi.org/10.1063/5.0033291 .