title: Technique of labeling monocytes with 111In-Fe colloid for use in humans.
abstract: In order to follow monocyte kinetics in hematologic malignancies by means of radioactive labeling, three conditions are necessary: (a) no loss of monocytes during separation, (b) specific labeling of monocytes, and (c) normal functional capacities of the labeled monocytes. In this report a method is described that fulfills the first two conditions and can be executed with maintenance of sterility. Cell labeling was performed using a mononuclear cell suspension consisting of monocytes (20%-50%), lymphocytes (50%-80%), and with minor contamination by granulocytes, thrombocytes, and erythrocytes. This cell suspension was obtained by centrifugation of a leukocyte suspension on a gradient of 16% wt/vol and 22% wt/vol human serum albumin solutions. The recovery of monocytes with this enrichment method approached 100%. Monocytes were labeled by endocytosis of 111In-Fe colloid; monocytes were labeled significantly higher than lymphocytes (P less than 0.001) and granulocytes (P less than 0.01) (Wilcoxon's two-sample test). Cell viability after labeling was greater than 90%.
mesh_terms: D001345:Autoradiography / Q000379:methods; D002454:Cell Differentiation; D002469:Cell Separation; D002470:Cell Survival / Q000187:drug effects; D003102:Colloids; D005290:Ferric Compounds; D005296:Ferrous Compounds; D006801:Humans; D007204:Indium; D007501:Iron; D009000:Monocytes / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D011868:Radioisotopes
chemical_list: D003102:Colloids; D005290:Ferric Compounds; D005296:Ferrous Compounds; D011868:Radioisotopes; C044480:indium ferric colloid; D007204:Indium; C020758:indium trichloride; D007501:Iron; C029451:ferrous chloride