Fig. 4.

Evaluation of the duplex AlphaLISA performance. Assessment of the Acceptor-bead performance and comparison between Europium and Terbium based beads was carried out once for both the LB509 (a) and the 11A5 (b) antibodies. In both instances the biotinylated 4B12 antibody was used and signal to background ratio calculated against serial dilutions of h-asyn proteins spiked in naïve rat brain lysate. Presence of any hindrance of Acceptor-bead coupled antibodies against each other was assessed for LB509-Terbium (c) and 11A5-Europium beads (d). Cross-talk between the channels was assessed using the Resorufine/Amplex Red FP535 Terbium filter (e) and the Europium 615 filter (f). For these experiments the relevant analyte, Acceptor- and Donor-bead information is given under the x-axis. Both the hindrance of Acceptor-bead coupled antibodies and the channel cross talk were run twice. See Additional file 2: Figure S2 for a theoretical explanation of the phenomena. AU arbitrary units