Acetone/periodate-lysine-paraformaldehyde (PLP) fixation and improved morphology of cryostat sections for immunohistochemistry.

Cryostat sections are extensively used in the study of lymphoid tissues because the majority of antigens do not survive routine fixation and processing. A major disadvantage of cryostat section immunohistochemistry is their poor morphology. The use of periodate-lysine-paraformaldehyde (PLP) fixation regimes for cryostat sections was evaluated and compared with conventional acetone immersion. This fixation gives excellent morphology but poor immunostaining. The quality of immunostaining with a panel of 31 antibodies was good with brief acetone fixation followed by PLP fixation. Morphological preservation was very good. We suggest that acetone-PLP fixation is an improvement over acetone alone for cryostat section immunohistochemistry.