Chemotaxis radioassays: a simplified, quantitative method using technetium-99m radiocolloid labeled granulocytes

Selective labeling of phagocytes in human blood can be achieved by incubation of unseparated, heparinized blood with 99mTc-sulfur colloid. We have developed a method for quantitation of granulocyte chemotaxis using granulocytes labeled by this technique. The method was found to be more accurate and less tedious to perform than the conventional Boyden chamber chemotaxis assay. The assay was also less time-consuming and as quantitative as a previously described granulocyte chemotaxis radioassay in which 51Cr-labeled leukocytes were used. The simplicity and reliability of this technique and the ready availability of 99mTc-sulfur colloid may provide one standardized method for granulocyte chemotaxis quantitation in clinical and experimental medicine.