What is cell separation and cell sorting?

November 2016


We recognize that if you are reading this, you probably already understand or at least have a very good idea of what cell sorting and cell separation is. Still, you would be surprised by how many times we get asked questions like, “What is the difference between cell sorting and cell separation?”

We also get questions like, “What are the different ways to separate cells?” or “What is the difference between positive and negative cell separation?” 

In order to answer these questions, we have put together the summary below. In our experience, cell separation is all about isolating a cell population from other cells or biological samples.

Cell separation is the isolation of particular cell populations from a mixed population


What are different cell separation approaches?

Three Different Cell Separation Approaches

  • Positive Selection: When the cell type of interest is targeted by the removal mechanism and retained for downstream analysis. This is typically performed by targeting a cell surface marker (CD4, CD8, etc.) with a monoclonal antibody.
  • Depletion: When a single cell type is removed from a biological sample. For example, removal of red blood cells from peripheral blood mononuclear cells (PBMCs).
  • Negative Selection: Similar to depletion, but when several cell types are removed to leave one cell type untouched. For example, depletion of all cells except for T cells or removal of all cells except for B cells from samples like whole blood or bone marrow.  

What are example uses of cell separation?

Examples of Cell Separation

  • Capture of circulating tumor cells from blood
  • Isolation of immune cells from peripheral blood
  • Isolation of white blood cells from tissue
  • Separation of pathogenic bacteria from food

What are some common cell separation technologies?

Main Cell Separation Technologies

  • FACS (fluorescence-activated cell sorting): This technology labels cells with fluorescent markers, which could be based on internal or external markers of the cells. The cells are then measured and identified one at a time and then sorted based on the color of the marker.
  • MACS™ (magnetic-activated cell sorting): Magnetic particles (nanoscale and microscale) bind to cells through an antibody interaction with the cell surface markers. This allows for the targeted cells to be magnetically isolated from a sample.
  • BACS™ (buoyancy-activated cell sorting): Microbubbles bind to cells through antibodies binding to the surface of cells. The targeted cells are then removed from a biological sample through flotation.
  • Other technologies: There are other methods for separation, like microfluidics, centrifugation, filtration, etc.

If you are interested in learning more about cell sorting or want to try out Akadeum’s microbubbles, contact us today.