Final answer:
The acceptable upper limit for residual moisture in freeze-dried tissue is 8%, which is crucial for the sample's long-term storage and stability, taking into account the freeze-thaw cycle and potential damage due to water expansion when frozen.
Step-by-step explanation:
The acceptable upper limit for residual moisture in freeze-dried tissue, as measured by NMR analysis, is b. 8%. This specific moisture content is essential for ensuring the long-term storage, stability, and post-preparative integrity of the tissue. The 8% threshold is a balance that prevents too much moisture, which could lead to microbial growth or degradation, while also avoiding excessive dryness that might damage the tissue structure. Considerations for the moisture limit include the freeze-thaw cycle and the potential expansion and damage caused by water when it freezes, affecting biological cells. This carefully determined moisture level thus supports both the short-term and long-term preservation of biological samples.
The acceptable upper limit for residual moisture in freeze-dried tissue, as measured by NMR analysis, is 10% (option c). Freeze drying is a process used to remove moisture from biological samples while preserving their structure and properties. It involves freezing the sample and then subjecting it to a vacuum environment, causing the ice to sublimate directly from the frozen state to a vapor.