Histomorphometric analyses of human adipose tissues using intact, flash-frozen samples.

TitleHistomorphometric analyses of human adipose tissues using intact, flash-frozen samples.
Publication TypeJournal Article
Year of Publication2018
AuteursLaforest, S, Pelletier, M, Michaud, A, Daris, M, Descamps, J, Soulet, D, Jensen, MD, Tchernof, A
JournalHistochem Cell Biol
Date Published2018 Mar
KeywordsAdipose Tissue, Freezing, Humans, Immunohistochemistry, Specimen Handling, Staining and Labeling

Histomorphometric analyses of adipose tissue usually require formalin fixation of fresh samples. Our objective was to determine if intact, flash-frozen whole adipose tissue samples stored at - 80 °C could be used for measurements developed for fresh-fixed adipose tissues. Portions of adipose tissue samples were either formalin-fixed immediately upon sampling or flash-frozen and stored at - 80 °C and then formalin-fixed during the thawing process. Mean adipocyte diameter was measured. Immunohistochemistry was performed on additional samples to identify macrophage subtypes (M1, CD14 + and M2, CD206 +) and total (CD68 +) number. All slides were counterstained using haematoxylin and eosin (H&E). Visual inspection of H&E-stained adipose tissue slides performed in a blinded fashion showed little or no sign of cell breakage in 74% of frozen-fixed samples and in 68% of fresh-fixed samples (p > 0.5). There was no difference in the distribution frequencies of adipocyte sizes in fresh-fixed vs. frozen-fixed tissues in both depots (p > 0.9). Mean adipocyte size from frozen-fixed samples correlated significantly and positively with adipocyte size from fresh-fixed samples (r = 0.74, p < 0.0001, for both depots). The quality of staining/immunostaining and appearance of tissue architecture were comparable in fresh-fixed vs. frozen-fixed samples. In conclusion, intact flash-frozen adipose tissue samples stored at - 80 °C can be used to perform techniques conventionally applied to fresh-fixed samples. This approach allows for retrospective studies with frozen human adipose tissue samples.

Alternate JournalHistochem. Cell Biol.
PubMed ID29356964
Grant ListMOP-102642 / / Institute of Gender and Health /