The MagDot is a dual-purpose reagent, it combines quantum dots and superparamagnetic iron oxide particles within the same nanoparticle. Cells labeled with MagDots targeting specific antigens will be both fluorescent and magnetic. Therefore, after labeling cells of interest, one can look at the feed to determine the percent positive fluorescently via flow cytometry, and then place the labeled cells in a magnetic separator and analyze both the magnetic (for the enrichment) and the nonmagnetic (for the depletion) of targeted cells without the need for further fluorescent labeling. The UCHT1 antibody conjugated to this MagDot reacts with the 20 kDa CD3ε subunit of the human T cell receptor (TCR)/CD3 complex, which is expressed on the surface of ~95% of mature T cells and NKT cells, and variably on thymocytes. A majority of T cell neoplasms also express CD3. The CD3 complex, which is assembled from combinations of CD3γ, δ, ε, η, and ζ subunits, associates non-covalently with the TCR and is involved in transducing antigen recognition signals into the cytoplasm of T cells and in regulating the cell surface expression of the TCR.