Fixation and long‐term storage of human lymphocytes for surface marker analysis by flow cytometry

Abstract

A method to preserve stained human lymphocytes for subsequent cell surface analysis by flow cytometry (FCM) is described. Cells stained with fluorescein isothiocyanate (FITC) and phycoerythrin (PE)‐conjugated monoclonal antibodies and then fixed in 1% paraformaldehyde, followed by extensive washing and resuspension in 1% BSA medium, could be stored at 4°C for at least 2 weeks prior to FCM analysis without significant alteration in the light scatter or fluorescence properties of the cells. Furthermore, the method was also suitable for analying lymphocytes that express T‐cell activation markers in certain disease conditions. In addition, we have identified monoclonal antibody combinations that discriminate different lymphocyte subsets that are satisfactory for multiparameter analysis after 2 weeks of storage. This method should prove useful for enumerating lymphocyte subsets in field study sites remote from flow cytometry laboratories. Copyright © 1988 Wiley‐Liss, Inc.