I'm developing a lateral flow immunoassay in competitive format, and once I printed and built the complete strip I test it with different concentrations of the analyte (resuspended in acetate buffer) diluted in running buffer (Hepes + NaCl + Tween 20 + BSA). The attached image is the result I got. The more analyte concentration I used, the lower the signal of the control and test line I got. And the membrane increased its opacity too.
Can someone help me understand what could be going on?