Microfluidic passive cell sorting
Microfluidic passive cell sorting is a technique used in microfluidics, a field that deals with the manipulation of very small volumes of fluids, typically on the microliter (10^-6 liters) or nanoliter (10^-9 liters) scale, to perform various biological and chemical processes. In passive cell sorting, cells or particles are separated or sorted based on their physical properties, such as size, shape, density, or deformability, as they flow through microchannels and interact with carefully designed structures within the microfluidic device. Importantly, passive cell sorting does not require external forces or active mechanisms (such as electric or magnetic fields) to perform the separation; instead, it relies on the inherent characteristics of the particles and the microchannel geometry.
Here's a step-by-step explanation of how passive cell sorting typically works in a microfluidic system:
Microfluidic Device Design: The microfluidic device is designed with specific structures or obstacles within the microchannels. These structures can include constrictions, filters, or curvatures strategically placed to exploit the physical properties of the target cells or particles.
Cell Sample Loading: The cell sample, which may contain a mixture of different types of cells or particles, is introduced into the microfluidic device. This sample is typically suspended in a buffer or carrier fluid, and it flows through the microchannels under controlled conditions.
Hydrodynamic Forces: As cells flow through the microchannels, they experience various hydrodynamic forces, such as inertial lift, shear forces, and drag forces. These forces depend on the cells' size, shape, and deformability.
Passive Sorting: The microchannel geometry and the applied fluid flow conditions are designed to exert differential forces on the cells or particles based on their physical characteristics. Cells that meet specific criteria (e.g., larger size, higher deformability) will experience different forces than those that do not.
Separation: As a result of these differential forces, the cells or particles are directed into different outlets or flow paths within the microfluidic device. Cells with desired properties are effectively sorted from the mixture.
Collection: The sorted cells or particles are collected in separate containers or chambers for further analysis or downstream applications.
Benefits of microfluidic passive cell sorting include its simplicity, low power requirements, and the ability to sort cells gently without exposing them to harsh external forces. It finds applications in various fields, including biology, biotechnology, and medical diagnostics, for tasks such as isolating rare cells from a blood sample, selecting specific cell types for analysis, or purifying particles based on their physical properties.
Here's a step-by-step explanation of how passive cell sorting typically works in a microfluidic system:
Microfluidic Device Design: The microfluidic device is designed with specific structures or obstacles within the microchannels. These structures can include constrictions, filters, or curvatures strategically placed to exploit the physical properties of the target cells or particles.
Cell Sample Loading: The cell sample, which may contain a mixture of different types of cells or particles, is introduced into the microfluidic device. This sample is typically suspended in a buffer or carrier fluid, and it flows through the microchannels under controlled conditions.
Hydrodynamic Forces: As cells flow through the microchannels, they experience various hydrodynamic forces, such as inertial lift, shear forces, and drag forces. These forces depend on the cells' size, shape, and deformability.
Passive Sorting: The microchannel geometry and the applied fluid flow conditions are designed to exert differential forces on the cells or particles based on their physical characteristics. Cells that meet specific criteria (e.g., larger size, higher deformability) will experience different forces than those that do not.
Separation: As a result of these differential forces, the cells or particles are directed into different outlets or flow paths within the microfluidic device. Cells with desired properties are effectively sorted from the mixture.
Collection: The sorted cells or particles are collected in separate containers or chambers for further analysis or downstream applications.
Benefits of microfluidic passive cell sorting include its simplicity, low power requirements, and the ability to sort cells gently without exposing them to harsh external forces. It finds applications in various fields, including biology, biotechnology, and medical diagnostics, for tasks such as isolating rare cells from a blood sample, selecting specific cell types for analysis, or purifying particles based on their physical properties.