Figure 1. Synthesis of MBs for isolation.

A, MBs were coated with anti-EpCAM antibodies in a two-step process as described in Methods; Based on the quantification (Supplement), on average 367,000 anti-Fc IgG molecules were coupled to the surface of each MB via Michael addition; B, anti-EpCAM was detected with Alexa 488-labeled secondary Ab. Size bar, 20 µm; C, Size distribution of IgG coated MBs as determined from microscopy images.