Used in immunology research to study T cell activation and immune responses in non-human primates. The CD3d protein with Fc tag enables detection, purification, and functional assays through its binding to anti-Fc antibodies or Fc receptor-expressing cells. Commonly applied in flow cytometry, ELISA, and immunoprecipitation to analyze T cell receptor complexes. Supports development and testing of therapeutic antibodies by serving as a reagent in cross-reactivity studies. Facilitates evaluation of drug effects on primate immune systems prior to human clinical trials.