Many diseases, including cancers, AIDS, diabetes, asthma, Parkinson's, and lymphoma, are associated with the immune cell responses of patients suffering from them. Identifying the underlying immune response in such diseases is critical to correctly diagnose their root cause and determine the correct medications to target that root cause for personal therapy and immunotherapy. This work focuses on small molecular CF dyes to conjugate with antibodies, such as CD4 and CD19, for their application in flow cytometry. The CF dyes enable the expansion of flow cytometry reagent panels to support high dimensional flow cytometry analysis of the resulting emissions of 30-40 fluorescent colors, a record in flow cytometry. The CF dyes can be used along with existing flow cytometry dyes to provide a quick, accurate, and cost-effective method for the diagnosis and immunology treatment of diseases such as minimal residual disease (MRD) after cancer therapy. The CF dyes will also be an effective tool for the clinical studies of immune response to SARS-CoV-2 and the related vaccine development.