This is a fairly easy protocol that does not disappoint. The antibody manufacturer is Sigma Aldrich Cat# MAB5268 a trusted name for antibodies. The antibody is a mouse monoclonal suitable for IHC (paraffin) and western blot for the following species; human, porcine, pig, rat, monkey, and mouse. It was tested by me using only human tissues.

Data Sheet not available but manufacturer website pdf here.

The human protein atlas has some good information about chromogranin A.