A single-pass high information-content binding curve of the CTB/GM
interaction. (A) 8 different concentrations of ganglioside GM1 (0.00, 0.02, 0.05, 0.10, 0.18, 0.25, 0.35 and 0.50 mol %) are microarrayed in the pattern of an arrow. The chips were then exposed to a fluorescently-labeled CTB, revealing the variation in GM1 concentration. (B) This experiment was performed on 8 different supported membrane chips. Using the microarrayer, the eight 8 × 8 chips were prepared with the same distribution of ganglioside GM1. They were subsequently exposed to different concentrations of fluorescently-labeled CTB. The arrays were imaged microscopically and fluorescence was quantitated using Adobe Photoshop.