The Q-Prep system: Effects on the apparent expression of leucocyte cell surface antigens

Abstract

To facilitate the analysis of immunolabelled peripheral blood or bone marrow leucocytes by flow cytometry, a number of reagents are available commercially that lyse erythrocytes and fix leucocytes. This study has investigated the effect on antibody‐labelled whole blood of the Q‐Prep procedure, in which erythrocytes are lysed with formic acid, and leucocytes are fixed with formaldehyde. Whole blood samples were labelled with the nuclear dye LDS‐751 and with antibodies to HLA‐DR or belonging to CD2, CD3, CD4, CD7, CD8, CD10, CD13, CD14, CD19, CD20, CD29, CD33, CD45, CD45RA, CD56, and CD62L (TQ‐1) that were directly conjugated to either phycoerythrin (PE) and/or fluorescein isothiocyanate (FITC). Leucocytes were analysed by flow cytometry either in unfixed, unlysed whole blood (15) or after preparation using the Q‐Prep system. The binding of eight antibodies, CD19‐FITC, CD2‐PE, CD3‐PE, CD4‐PE, CD19‐PE, CD29‐PE, CD45RA‐PE, and CD56‐PE, to the surface of lymphocytes was reduced, resulting in significant changes (P < 0.05) in the percentages of cells that stained positively and/or their mean molecules of equivalent fluorochrome (MEF). Further analysis revealed that this was due to the formic acid used during the erythrocyte lysis stage. Cytometry 30:67–71, 1997. © 1997 Wiley‐Liss, Inc.

ISHAGE-based single-platform flowcytometric analysis for measurement of absolute viable T cells in fresh or cryopreserved products: CD34/CD133 selected or CD3/CD19 depleted stem cells, DLI and purified CD56+CD3− NK cells

“…Red cell lyses can change cell characteristics, a phenomenon well known from CD34 + analysis. One should be aware of the alterations in the antibody binding and scatter characteristics of the white cells in the probe [25,26].…”

Effect of type of TAG fatty acids on lutein and zeaxanthin bioavailability

“…An example of reference ranges for lymphocyte subsets in different age groups has been given in several publications ( 56 – 59 ) . However, most of these markers are basal markers involving the enumeration of cells or factors in a sample without controlled experimental stimulation to assess a specific functional response.…”

Comparative study of five commercial reagents for preparing normal and leukaemic lymphocytes for immunophenotypic analysis by flow cytometry

“…Several studies have investigated the merits of these different reagents (3,10,11,14,15). In most cases, these studies have used blood from normal individuals (3,10,11,14). It is therefore of interest to know whether such reagents could alter results obtained from the immunophenotypic analysis of leukaemic samples and so influence the diagnosis.…”

“…The commercial reagents utilised different erythrocyte lysing agents, but all included formaldehyde as a fixative. In this study, we have therefore not addressed the problems associated with erythrocyte lysis without subsequent fixation of the leucocytes, although previous preliminary work by us suggest that this later procedure is best avoided (11). We selected for analysis antibodies which detected antigens that are either strongly (CD3, CD5, CD45), moderately (FMC7, , and ), or weakly (CD11b) expressed on normal lymphocyte subsets.…”