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Long-term storage at -20°C compromises fatty acid composition of polar bear adipose biopsies

February 8, 2024

This study aimed to gain insight into the influence of storage time and temperature on fatty acid (FA) signatures of biopsies of marine mammal adipose/blubber tissues. To examine storage effects, biopsy-type slices from larger pieces of adipose tissues from 2 polar bears Ursus maritimus were stored at either -20 or -80°C and subsequently analyzed for fatty acid composition initially (before storage), after 4 yr, and after 9 yr. At -20°C, after both 4 and 9 yr, proportions of polyunsaturated FAs significantly decreased, and proportions of monounsaturated FAs increased. Proportions of saturated FAs significantly increased only after 9 yr at -20°C in samples of 1 individual. After 4 and 9 yr of storage at -80°C, proportions of the 3 FA classes did not significantly change overall. Intra-individual differences in FA proportions increased over time in -20°C conditions, further pointing to biases stemming from inadequate storage conditions. These findings support the need to store biopsied fatty tissues (or other similarly thin and/or small adipose/blubber samples) at or below -80°C to adequately preserve FA signatures in samples over time for retrospective applications such as dietary studies.

Publication Year 2024
Title Long-term storage at -20°C compromises fatty acid composition of polar bear adipose biopsies
DOI 10.3354/meps14501
Authors Rose Lacombe, Todd C. Atwood, Elizabeth Peacock, Anais Remili, Rune Dietz, Christian Sonne, Melissa McKinney
Publication Type Article
Publication Subtype Journal Article
Series Title Marine Ecology Progress Series
Index ID 70251378
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Ecosystems