A rapid, no-wash technic for immunophenotypic analysis by flow cytometry.

With the advent of fluorochrome-labeled monoclonal antibodies, it has now become possible to eliminate the removal of unbound antibodies during immunophenotypic analysis of lymphoid cells by flow cytometry. Suspensions of mononuclear cells from healthy controls and fluoresceinated monoclonal antibodies may be introduced directly into the flow cytometer. The percentage of nonwashed antibody-positive cells from healthy controls as compared with the conventional technic of cell washing shows a good correlation. However, the correlation is not as good when the lymphocytes from certain classes of diseased patients are analyzed. It appears that excessive washing in fact produces erroneous results for certain markers with cells from diseased patients. The no-wash technic is also applicable to various combinations of dual-fluorescence monoclonal antibody staining. This technic substantially reduces the processing time and, more importantly, eliminates some of the cell losses and artifacts induced during the process of cell washing. The shortened processing time has allowed rapid responsiveness in certain urgent clinical situations.