Flow cytometric sorting of eosinophils using autofluorescence and light scatter patterns. (A) Peripheral blood leukocytes from case 1 were obtained from whole blood after removal of erythrocytes by lysis and analyzed on a FACStarPLUS flow cytometer. (AI) The populations of leukocytes were differentiated by their side scatter and autofluorescence patterns: eosinophils (R1, 57.9%), granulocytes (R2, 26.5%), and lymphocytes (R3, 12.8%). Cells of the region R1 exhibited marked autofluorescence that was detected on FL1, and to a lesser extent, on FL2. Cells in R1 were sorted into sterile tubes containing 2 mL of sterile PBS (pH 7.4). (AII) Resultant cell populations contained 98.5% eosinophils (R1), 1.0% granulocytes (R2), and 0.4% lymphocytes (R3). (B) Twenty-six months later, peripheral blood leukocytes from case 1 were obtained and again analyzed on a FACStarPLUS flow cytometer. (BI) Eosinophil (R1, 6.0%), granulocyte (R2, 74.0%), and lymphocyte (R3, 17.3%) populations were noted among the leukocytes. Cells in R1 were purified by flow cytometric sorting. (BII) The resultant cell populations contained 92.0% eosinophils (R1), 4.0% granulocytes (R2), and 4.0% lymphocytes (R3).
