Differential Scanning Calorimetry

Extraction of the perimysial connective fraction was conducted according to procedures described by Light and Champion (1984) with modifications. Briefly, 1 g of diced sample was weighed and half (0.5 g) of the sample was homogenized in 1 mL of 0.05 M CaCl₂. The homogenate was filtered through a 1-mm² mesh screen. The remaining 0.5 g of sample was homogenized and filtered in a similar manner. Material that did not pass through the mesh screen from the two 0.5-g extractions was combined and homogenized in 1 mL of the same CaCl₂ solution and refiltered a total of 3 times. At the end of the extraction, any nonfiltered material was deemed the perimysial fraction and was lyophilized before being subjected to differential scanning calorimetry (DSC) procedures described by Li et al. (2008) with modifications. Five milligrams of sample was weighed into aluminum pans and sealed. Samples were scanned from 0 to 100°C with a 5°C/min temperature increase using a Shimadzu 201-52943 DSC (Shimadzu Scientific Instruments, Kyoto, Japan). The maximum transition temperature was estimated using TA-60WS software (Shimadzu Scientific Instruments).