The eBioscience 1-step Fix/Lyse Solution enables lysis of red blood cells after staining peripheral blood cells with fluorochrome-conjugated antibodies. This solution has been specially formulated to lyse non-nucleated erythrocytes while maintaining a fixed and labeled leukocyte population. Therefore, whole blood samples can be stained for the appropriate markers, RBC-lysed and fixed, washed, and then analyzed by flow cytometry. Isolation of mononuclear cells by gradient centrifugation (e.g. Ficoll-Paque density gradient separation) is not required when using this solution. The eBioscience 1-step Fix/Lyse Solution is compatible with antibodies conjugated to organic dyes and tandem dyes.