Figure 2. Flow cytometry analysis of the binding ability of the evolved ssDNA pools.

A. The fluorescence intensity of 5-8F cells was gradually increased after incubation with increasing rounds of ssDNA pools. B. No increase in fluorescence signal was observed for negative control NP69 cells after incubation with ssDNA pools. No obvious binding on lung adenocarcinoma A549 cells C. and gastric carcinoma GBC823 cells D. were observed after incubation with the 25^th round ssDNA pool. It implied that the selected DNA pool might specifically bind to NPC cells. The unselected initial ssDNA library was used as a control.