Hi,

In our lab we have been performing perfusions and immunohistochemical stainings for the dopaminergic marker TH combined with Nissl, on mouse brain tissue for many years.

Once in a while, we had artifact where we couldn't detect any dopaminergic neurons in our staining. More recently it has been happening a lot and we cannot figure out what causes this. Different people in our lab have this problem in different experimental groups & conditions. We have tested multiple perfusion techniques, different antigen retrieval protocols and adding heparin to the perfusion. Unfortunately it keeps happening to randomly and we don't have any more ideas on why this is happening.

Does anyone have any experience with this and knows what is causing this?