Figure 1. Cytospots prepared with human peripheral blood mononuclear cells (PBMCs) isolated from leukocyte filters or heparinized blood showed no morphological differences in the lymphocytes resulting from the preparation techniques.

A) PBMCs isolated from a leukocyte filter. The left cell displays an NK cell expressing CD56 (red) and the leptin receptor (Ob-R, blue). The hematoxylin stained lymphocyte (right) is negative for CD56 and Ob-R. B) The representative cytospot prepared with PBMCs isolated from heparinized blood shows a CD56/Ob-R double-positive NK cell (top), a CD56-positive lymphocyte (middle) and a double-negative lymphocyte counterstained in hematoxylin.