Figure 1. Quantitative receptor binding
(a) Typical dose response curve for the
quantitative potency assay. The pVGI.1(VEGF2) reference standard was
pre-diluted to the starting concentration of 25 mg/mL before the 1:1 serial
dilutions with the formulation buffer. The VEGF-2 in the conditioned media of
the transfectants was then assayed for VEGFR3 binding activities (A450). The
average of triplicate raw OD results was then plotted against the input DNA
concentration in the transfection mix. The standard curve was modeled using a 4
parameter fit by SoftMax Pro v.3.1.
(b) The expected potency value vs. the
measured potency value for the concentration range of 60-140% with the regression
line (y = 0.949 x + 1.1617).
(c) Specificity of the binding reaction.
The receptor binding detection was specific to the VEGF-C protein. Serially
diluted protein was loaded on the plate and the binding signals were detected
by OD450. The background was assessed using BSA buffer that did not
contain any protein from the VEGF family.