Fig. 5
Antibody selection through specific binding and hopping. E. coli and S. flexneri are trapped in the hotspot after they are conjugated with biotin-labelled anti-E. coli antibody and biotin-labelled anti-S. flexneri antibody, respectively. When a streptavidin-conjugated microparticle passes through the trapped a E. coli and c S. flexneri stained with specific antibodies, the microparticle is anchored to the bacterium through the very strong biotin–streptavidin interaction. The microparticle and bacterium hop together to another hotspot. When b E. coli and d S. flexneri are trapped in the hotspot after they are incubated with non-specific antibodies, the streptavidin-conjugated microparticle hops to another hotspot without binding with any bacterium due to the unsuccessful labelling of biotin. Experimental observation of the streptavidin-coated microparticle hopped with e E. coli conjugated with anti-E. coli antibody, and f passed away from bare E. coli due to unsuccessful conjugation of non-specific antibody (anti-S. flexneri antibody)
