The difference between the assembly of MBT2 cells with anti-HER2- modified and IgG-modified spheres is observed to be diacritic under optical microscopy and by measuring the extinction coefficient of specific wavelengths of visible light, indicating that micrometer and submicrometer spheres can be bound to the surfaces of cells by such a weak interaction between the anti-HER2 antibody and extracellular domain of the HER2 protein (92-95% with Kd ≈ 10-9 M, others