Immunogold staining: adaptation of a cell-labeling system for analysis of human leukocyte subsets.

We have assessed the Immunogold Cell-Labeling System (IGS) for potential use in the clinical laboratory. In this technique, cell suspensions incubated with monoclonal mouse antibodies are reacted with anti-mouse antibodies labeled with colloidal gold. Surface marker cells, bearing dark blue-black granules, are easily distinguished by light microscopy. The percentages of T cells, T cell subsets, B cells, monocytes, or granulocytes identified by IGS corresponds with numbers obtained by flow cytometry analysis or immunofluorescence studies. Results by IGS and flow cytometry were similar for samples from patients with aberrant lymphocyte populations (e.g., leukemias) or from transplant recipients. IGS may thus be a useful diagnostic technique for studying neoplasias or other immunologically mediated disorders. This technique can also be used to characterize the surface phenotype of leukemic cell lines. The sensitivity and accuracy of IGS can be evaluated by measurements of different cell lines mixed in predetermined ratios.