I used to do an immunoflouresence staining for my organotypic slice cultures. Now i need to shift for a DAB staining. However, we had found it very challenging. we ended up with a very high background and a messy crystal violet nuclei staining. Increasing the hydrogen peroxidase concentration up to 2% or/and the incubation time seems to be harsh for the slices, making it detached form the insert and curled up.. Can you share some of your working protocol?