Evaluation of tissue section cryostorage on immunohistochemistry (1050.1)

Abstract

Storage of tissue sections for significant periods is often required to allow tissue from multiple samples, acquired over months to years, to be processed together, in the same reagents, for quantitative studies using immunohistochemistry. Several protocols for storage in sucrose with different additives have been reported that assert there is no effect on immunogenicity. However, there have been no quantitative assessments of how long‐term frozen storage in any cryoprotectant affects immunogenicity. The present study analyzed existing datasets, derived from monkey brain sections stored at ‐80°C in 15% phosphate buffered glycerol to determine whether time frozen in this cryoprotectant affected stereology counts of cells immunostained for NeuN, Parvalbumin, Orexin‐A, Doublecortin, BrdU or pro‐BDNF. Multiple regression analyses controlling for age and sex of the subjects in the different data sets showed that time in 15% glycerol did not affect stereological counts for any marker. Experiments are underway to compare our 15% glycerol cryoprotectant to four 30% sucrose based cryoprotectants for preservation of immunogenicity after frozen storage. Grant Funding Source: Supported by NIH grants R01‐AG043640 and R01‐AG042512