Note variation in nuclear immunoreactivity, paraformaldehyde fixation. Right - PCNA in mouse liver preneoplastic focus. Both methods illustrate the same apoptotic bodies in the mousestomach. Cytoplasmic Antigens Left - Actin in myoepithelial cell. Slide courtesy of Dr. Sabine Rehm.
Ethanol is often the best fixative to use in order to demonstrate keratins.
Right - IgG in plasma cells in mouse lymph node. Immunoglobulins are best demonstrated with Bouin's, B-5 or paraformaldehyde fixation. Left - GSTP in human liver bile duct, ductule and oval cells. Note similarity to keratin in similar mouse liver lesions. Contrast with membrane staining seen above in tumor cells.