Enumeration, phenotyping, and identification of activation events in conjugates between T cells and antigen-presenting cells by flow cytometry.

Microscopic analysis of T cell-antigen-presenting cell (T cell:APC) interactions at the single cell level has been a powerful, but tedious and subjective, technique. In this paper, we describe a rapid and quantitative method to identify T cell:APC conjugates using succinimidyl ester dyes, which irreversibly label free amine groups on the cell surface. The labeled cell conjugates and subsequent activation events are detected by flow cytometry.