2021 November 4

New flow cytometry approaches to tell apart red from white blood cells

The Functional Cytomics group at the Josep Carreras Leukaemia Research Institute finds out new methods to enumerate and analyze subpopulations of cells in blood samples by using flow cytometry, instead of physical separation prone to cell lysis.

In a recent publication at STAR Protocols, a journal from the prestigious Cell Press editorial group, a team from the Josep Carreras Leukaemia Research Institute and Thermo Fischer Scientific lead by Dr. Jordi Petriz discusses the benefits of flow cytometry to separate and quantify cell types from fresh blood samples with minimum manipulation.

By using the new approaches, doctors can identify more confidently subpopulations of rare cells present in samples, like residual malignant leukemia cells after treatment or stem cells in a bone marrow extract. Being capable of detecting these scarce cells is key to certify complete remission in blood cancers or when preparing a bone marrow transplant.

Traditional cell-immunophenotyping methods imply several manipulations of the samples, including gradient centrifugations and aggressive washing steps, prone to cell lysis and cell loss. As a result, rare subpopulations of cells may disappear or be left underrepresented.

To avoid this, the team proposes two different methods, one taking advantage of the different light scattering properties of red blood cells (erythrocytes) versus white blood cells (lymphocytes), and the other by using fluorescent labeling of the cells. Regardless of the method used, by moving towards flow cytometry ensures minimal sample manipulation and a robust characterization of all cell populations.

The protocols made available to the international community are the result of over 20 years of experience using flow cytometry and will open the door to more efficient and less invasive screening methods leading to more precise and reliable results.

 Reference:

Laura G.Rico, Roser Salvia, Michael D.Ward, Jordi Petriz. “Flow-cytometry-based protocols for human blood/marrow immunophenotyping with minimal sample perturbation”. STAR Protocols, Volume 2, Issue 4, 2021 11 Oct 2021. https://doi.org/10.1016/j.xpro.2021.100883