Capture and isolation of single cells are prerequisites for understanding these cellular variations. However, efficient single cell capture and isolation are complex tasks for any cell population. Therefore, many technologies for single cell capture and isolation have been developed.
Microfluidics, a technology of manipulating fluid in channels with dimensions of tens of micrometers, has recently emerged as a major new area of research due to its application in so many other fields, including chemistry, biology, medicine, and the physical sciences. Conventional cell capture and isolation methods cannot easily manipulate single cells in standard Petri dishes because of the cell sizes. Microfluidic technologies emerge as potentially powerful tools for precise control and efficient capture of target single cells from a cell mixture.
Fig.1 Schematic overview of different microfluidic methods for single-cell isolation. (Gross, 2015)
Most of these Microfluidic devices use at least one of the three following principles to isolate single cells:
- Droplet-in-oil-based isolation.
- Pneumatic membrane valving.
- Hydrodynamic cell traps.
Droplet microfluidic uses a 2-phase system, in which each assay is categorized in an aqueous microdroplet (1 pL to 10 nL) surrounded by an immiscible oil.
The advantages of this droplet-based technique include:
- The physical and chemical isolation of droplets eliminates the risk of cross-contamination.
- The fast and efficient mixing of the reagents that occur inside the droplet.
- The ability to manipulate droplets at a very high throughput digitally.
- The ability to incubate stable droplets off-chip and reintroduce them into the microfluidic environment for further processing and analysis.
- The absence of moving parts.
Pneumatic Membrane Valve (PMV)
PMVs use pressurized air to deflect an elastomer membrane, which closes a microfluidic channel below, allowing for digitally opening or closing channels in a microfluidic network. However, valve-based approaches need a cell detection unit or an operator to isolate cells individually.
Hydrodynamics traps are a type of passive structure in the microfluidic channel that allows only one cell to enter at any time. This can be accomplished by adjusting trap size based on average cell sizes found within samples, which results in many cells being able to occupy these same traps simultaneously. For example, commercial system C1 from Fluidigm Corp. allows for parallel isolation and subsequent genetic analysis of 96 individual cells. Hydrodynamic trapping can even be integrated into handheld pipettes to enable manual single-cell pipetting without micromanipulation under a microscope.
Creative Biolabs offers efficient and detailed support to bring automation to your application workflows. Our Single Cell Sorting and Isolation Platform can provide highly customized comprehensive solutions with the best quality to advance our global clients' projects. Any requirements, please feel free to contact us for further communication about your project.
- Gross, A.; et al. Technologies for single-cell isolation. International Journal of Molecular Sciences. 2015, 16: 16897-16919.
- Brouzes, E.; et al. Droplet microfluidic technology for single-cell high-throughput screening. Proceedings of the National Academy of Sciences. 2009, 106:14195-14200.