Representative examples of gating of blasts by 3-color FCM.

(A) Data are shown for 4 cases for which the BR interface contained various percentages of blasts. The percentages of blasts determined in cytospin preparations were 96%, 17%, 66%, and 22% for cases 1 through 4, respectively. The samples subjected to BR density centrifugation were PB for cases 1 and 2 and BM cells for cases 3 and 4. The upper panels are CD45 versus SSC displays in which R1, R2, R3, and R4 are gates for blasts, lymphocytes, monocytes, and erythroid cells, respectively. The rectangle in case 4 shows the gate for myeloid cells other than myeloblasts. The gated cells in R1 through R4 are shown as green, red, black, and yellow dots, respectively, in the lower panels, which show the FSC versus SSC displays for each case. (B) Examples of antigen expression analysis of blasts (cells in R1) by FCM for case 4.