I am recently observing DAB staining fail-regions (red circles or red arrows on pictures) on my DAB stained slides. Does anyone have ideas why I am getting this?
I can see only hematoxylin stained cells even in DAB positive area. But sometimes both DAB and hexatoxylin stainings were not stained in the fail-regions.
I used Leica BOND RX automated machine plus DAB staining kit for the DAB staining.
I baked the slides at 65 °C for 3 hours, so I don't think the fail-regions are because of not melted paraffin.
Moreover, the fail-regions are not seemed bubbles, because the shape is different from that of typical round bubbles(blue arrows in DAB-fail 3).
Does anyone experienced like this result? or has seen or solved the issue?