1 1 dioctadecyl 3 3 3 3 tetramethylindocarbocyanineperchlorate

2-distearoyl-sn-glycero-3-phospho-ethanolamine-N-[maleimide (polyethylene glycol)-3400] (DSPE-PEG₃₄₀₀-Malemide) was purchased from Laysan Bio, Inc. (Arab, AL, USA) and stored in chloroform as 3.4 mM solution. Traut’s reagent (2-iminothiolane) was purchased from Thermo Fisher Scientific (Rockford, IL, USA). The reagent was dissolved in double-distilled water at 5 mg/ml and stored in aliquots at −20° C. AffiniPure Fc fragment specific IgG was purchased from Jackson ImmunoResearch (West Grove, PA). Mouse anti-human and rat anti-mouse CD326 (EpCAM) antibodies were purchased from Bio Legend (San Diego, CA, USA). Rat anti-mouse anti-CD45 antibody was purchased from BioLegend (San Diego CA). 1,1′-dioctadecyl-3,3,3′3′-tetramethylindocarbocyanine perchlorate (DiI) was from Biotium (Hayward, CA). Anti-CD20 humanized antibody (Rituximab, Genentech) was obtained from UCSD Moores Cancer Center Pharmacy. AlexaFluor 488 goat anti-rat antibody and AlexaFluor 488 goat anti-human antibody were purchased from Life Technologies (Carlsbad, CA). FITC mouse anti-human CD19 (clone HIB19) antibody and FITC mouse anti-human CD45 (Clone H130) antibody were from BD Biosciences (La Jolla, CA). FITC labeled rat anti mouse CD45 antibody and FITC labeled rituximab antibody were synthesized in the laboratory.