Have you thought of degranulated granulocytes? If you are using a light scatter gate, these cells will look like lymphocytes, have CD45 (though somewhat dimmer than lymphs), and may be of considerable number if using old blood. -----Original Message----- From: Mikayla Kob [mailto:kob@cbr.med.harvard.edu] Sent: Wednesday, June 06, 2001 4:41 PM To: cyto-inbox Subject: CD45 negative PBL? Dear cytometry community, We have been establishing a panel to phenotype lymphocytes from clinical peripheral blood samples. We have been using a whole blood staining and lysis procedure. The samples that I have received so far have had an unusually large percentage of CD45- cells (over 50%) in the lymphocyte gate as determined by forward and side scatter. These cells are also CD3, 4, 8, and 19 negative, appear to be CD43 negative, and are not NK cells. It may be helpful to know that these samples had very poorly defined populations in the forward vs. side scatter plot. I have not yet tried erythrocyte or platelet stains to rule out aggregates or nucleated red blood cells, nor have I tried staining isolated mononuclear cells. Does anyone have an idea what these cells may be? Could anither cell fraction with these scatter qualities potentially be large enough to make up over 50%? Has anyone had any experience with a pathological state of which this may be symptomatic or for which whole blood staining and lysis may yield erroneous results? Any information or advice would be appreciated. Thank you in advance. Sincerely, Mikayla Kob kob@cbr.med.harvard.edu <mailto:kob@cbr.med.harvard.edu>
This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:57:43 EST