I have stained a slide of normal human tissues with a specific antibody against my protein of interest. What I observed is that in some tissues like lung and kidney, there are brown spots whereas in liver it is more like cytoplasmic brown staining. I have attached a photo of lung, I would appreciate any comment, since I have never done this before and do not have any idea as to what it might be.
Thanks a lot.
PS: Initially I thought it might refer to localization in one of the organelles, but in some cells there are three or four of those spots,...what can it be?