Tissue fixation methods alter the immunohistochemical demonstrability of neurofilament proteins, XXXX , and glial fibrillary acidic protein in human cerebellum.

@entity5473 @entity1885 @entity406 @entity538 @entity3125 @entity1604 @entity2383
This study has examined the effect of postmortem autolysis, type, and duration of fixation on neurofilament, @entity5473 , and glial fibrillary acidic protein ( @entity538 ) antigen decay as demonstrated by immunohistochemistry, using a streptavidin- @entity1885 peroxidase method. The system used consisted of 5 normal cerebellar cortices. Time intervals, temperature, mode of fixation and storage, and staining technique were well controlled. Anti-neurofilament antibodies comprised SMI-31, MNF, and BF-10 against @entity2383 , and SMI-32 against a non-phosphorylated epitope. Bouin's and B5 fixative, and Sensofix gave best results, whereas @entity406 and @entity1604 fixation gave much lower immunoreactivity. Phosphorylated neurofilament epitopes were less affected by @entity3125 than unphosphorylated epitopes. @entity538 staining was most consistent after Bouin fixation while the monoclonal antibody was much more sensitive to the fixative used than the polyclonal one. Aspecific background staining increased considerably after a postmortem interval of 24 hours. @entity5473 immunoreactivity, as demonstrated by SY-38, proved very sensitive to prolonged fixation and was of poor quality following @entity406 and @entity1604 fixation. Knowledge of antigen decay due to postmortem artifacts is essential for the correct evaluation of immunoperoxidase studies of autolyzed tissues that have been fixed and stored in different modes and for variable time interval.
