We also performed the same experiment with a noncovalent florescent cargo molecule in a competing presence of no fluorophore tagged non-covalent cargo (150 kD D-lysine chain polymer) for 30 minutes. The results indicate that the green fluorescence intensity on the surface of live cells conjugated with fluorophore-tag non-covalent cargo reduced significantly, compared to fluorophore-tag covalent cargo cell surface conjugation (Figure and Figure ). ). Our data indicate additional bonding interactions of the dual-conjugated covalent cargo, compared to the non-covalent cargo, with cell surface based on our cargo design strategies. Keeping cells alive after cell surface conjugation is a requirement for future applications. To see the cytotoxic effect of surface conjugation, we performed a viability test of the surface-modified Jurkat T cells for 6 days. We performed the cell-titer blue viability assay resulting in more than 95% surface-modified Jurkat T cells viability after 6 days (Figure ). Confocal 3D images of surface conjugated Jurkat T cell with the stable and nontoxic covalent fluorophore cargo is shown in Figure .