Figure 4

VEGF assay of human serum samples and control study. (A) 10-fold diluted and (B) undiluted human serum samples using anti-VEGF antibody (ab9570). The particle size change presented in both graphs is the difference between the size measured at 5 min after antibody addition and the size measured just before antibody addition. (C) 10-fold diluted human serum samples using anti-VEGF antibody (ab39250). The particle size change presented in the graph is the difference between the size measured before antibody addition and the size measured at 9 min after antibody addition. Also shown in (C) is the particle increase of the assay solution by adding a Rabbit IgG isotype control to the assay solution (data in blue colored columns). The particle size change presented in the graph is the difference between the size measured before antibody addition and the size measured at 9 min after antibody addition. Data presented in (A) and (B) were obtained using Malvern ZS90 DLS system; while data presented in (C) were obtained from Nano Discovery NDS-1200 system. Error bar shown in this graph is the standard deviation of two replicate assays.