Enhanced detection of eosinophils simultaneously with other leukocyte subsets using flow cytometry (TECH2P.902)

Abstract

Abstract Eosinophils differentiate in the bone marrow prior to migration to the vascular periphery and eventual residency in tissues. While they can either be a harmful or helpful component of the immune system, they help aid in the allergic response as well as modulate inflammation. Detection of eosinophils in blood samples was typically performed using H&E staining methods, however flow cytometric analysis of whole blood samples allows researchers to identify multiple cell types in a single sample that couldn’t be done before. Here, we were able to identify a distinct eosinophil population amongst clearly separated lymphocytes, monocytes, and granulocytes comparing FSC vs SSC using an ACEA NovoCyte flow cytometer. When compared to another flow cytometer, we were unable to clearly resolve other leukocyte subsets simultaneously with eosinophils; rather additional adjustments had to be made to resolve the eosinophil population at the expense of viewing the other leukocyte subsets. Eosinophils were also analyzed using their inherent auto-fluorescence in the FITC and PE channels, then back-gated to FSC vs SSC to confirm their identity. This shows that in order to identify multiple leukocyte subsets simultaneously using FSC vs SSC, a flow cytometer with a large dynamic range is essential for this type of analysis.