Acid Digestion
Acid digestion was used as an alternative to the enzyme digestion protocol above.
The tissue sample was transferred to a glass test tube and an equal volume of 60% nitric acid (Fisher Scientific) was added. The test tube was placed in a beaker of hot (94°C) water for about 1 hour or until the tissue was completely digested. The samples were then centrifuged and the pellet washed with dilute acid and finally resuspended in 0.1% of the aqueous surfactant FL-70.