Antibody vs. antigen titration.

<p>A) Polyclonal anti-SA antibody (4.16 nM to 66.6 nM), B) polyclonal anti-GST antibody (2.08 nM to 33.3 nM) and C) monoclonal anti-SA antibody (4.16 nM to 66.6 nM) were mixed with five different concentrations of Eu-SA and AF647-SA (at equimolar ratio), and resulting TR-FRET was measured. Dilution series of Fab fragments (7.5 nM to 120 nM) D) tested with 8 nM antigens (Eu-SA and AF647-SA). The TR-FRET (expressed in response counts) is the average of two measurements. Raw data are presented on the left panel, and the normalized data on the right panel. The concentration of specific IgG (for PAb), is indicated in brackets. Error bars are ± standard deviation calculated from parallel wells.