How are cells separated?

Cells may be separated from complex biological samples based on characteristics such as cell size, cell shape, cell density, and surface protein expression. The most common cell separation methods include Fluorescence-activated cell sorting, Magnetic-activated cell sorting, Buoyancy-activated cell sorting, Microfluidic-based cell sorting, and Spectral cell sorting. 

Fluorescence-activated cell sorting or FACS: This cell separation method uses fluorescent markers to label cells based on their internal or external characteristics. These labeled cells are then identified and measured individually before being sorted based on the color of their fluorescent marker. 

Magnetic-activated cell sorting or MACS: This technique separates cells using magnetic particles, which can bind to cells via the interaction of antibodies with the cell surface markers. Once the cells of interest have been targeted and labeled with magnetic particles, they can be easily isolated from the sample using a magnetic field. 

Buoyancy-activated cell sorting or BACS: This cell separation method uses low-density particles (microbubbles) to separate cells based on their buoyancy properties. Microbubbles bind to cells via surface marker antibodies. Only the microbubble-labeled cells float to the surface while the non-labeled cells settle at the bottom, allowing for easy separation and purification of the target cell population from a biological sample through flotation.

Microfluidic-based cell sorting: In the microfluidic cell sorting method, microfluidic cartridges are used to separate cells. The advantage of this technique is that it takes place in a sterile environment, eliminating the potential risks of aerosol generation or sample carryover. Additionally, the need for daily maintenance is eliminated, saving time and effort.

Spectral cell sorting: Although spectral cell sorting technology is based on the same principles as conventional cell sorting, it uses a different method to detect fluorescent signals. Spectral flow cytometry measures the complete emission spectrum of every fluorophore across a detector array, which allows for fluorophores with similar emission maxima to be combined in the same panel, providing more efficient and flexible sorting options.