We find that floating sections are stained more effectively compared to sections adhered to slides. When sections are adhered to slides, there are several potential problems since the access and penetration of the antibody beyond the surface of the sections is limited. You can overcome this to some degree by increasing the Triton X-100 content in the antibody solution. However, we don’t recommend this in many cases where the antibody targets an extracellular epitope because Triton X-100 is a relatively harsh detergent and too much can deteriorate the antigens.