Abstract
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.
Original language | English (US) |
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Pages (from-to) | 209-218 |
Number of pages | 10 |
Journal | Histochemistry and Cell Biology |
Volume | 149 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1 2018 |
Keywords
- Adipocyte hypertrophy
- Frozen tissue
- Image analysis
- Immunohistochemistry
- Macrophages
ASJC Scopus subject areas
- Histology
- Molecular Biology
- Medical Laboratory Technology
- Cell Biology