Improved cell surface radioiodination of macrophages.

Rabbit alveolar macrophages at high cell concentrations are inefficiently radiolabeled by the usual lactoperoxidase-catalyzed iodination method. Soluble macromolecules secreted by macrophages were found to inhibit the radioiodination of macrophages and other cells. A modified procedure is described which minimizes the presence of such inhibitory material and thereby considerably improves the radioiodination efficiency for both alveolar macrophages and the macrophage-like P388D1 cell line.