The recent review Stem cell separation technologies, comprehensively covers all current cell separation methods. The review includes classification of cell separation, overview of methods, pros and cons, challenges and future directions.

Cell separation techniques can be broadly classified into two categories: techniques based on physical parameters (size/density), and techniques based on affinity (chemical, electrical, or magnetic couplings).

The authors cover such separation techniques as:

  • fluorescence-activated cell sorting (FACS);
  • magnet-activated cell sorting (MACS);
  • preplating;
  • conditioned expansion media;
  • density gradient centrifugation;
  • field flow fractionation (FFF);
  • dielectrophoresis (DEP);
  • aqueous two-phase system;
  • systematic evolution of ligands by exponential enrichment (SELEX);
  • microfluidic platforms.

On future development:

Among the many stem cell separation methods, affinity-based approaches are so far most efficient and reliable, due to the high specificity of antibodies that recognize stem cell surface markers. FACS can achieve an impressive >95% purity, while MACS is portable. With growing knowledge on better stem cell markers, and the generation of more specific aptamers by SELEX, affinity-based techniques will still be very powerful in the future for stem cell separation.

As a method to isolate stem cells in an automated, miniaturized, multiplex, and portable fashion, microfluidics offer exciting solutions to these challenges. Although the purity of stem cell separation by microfluidic devices needs to be substantially improved, merging conventional technologies onto microfluidic platform will be extremely beneficial.

Most separation methods have room to increase throughput. Among them, FFF, DEP, and density gradient centrifugation show great potential in large-scale production.

This is the best review that I ever read on this subject. Highly recommended!