## Core Concept
Inspissation is a process used for sterilization and preservation of certain materials, particularly in microbiology and medical research. It involves heating materials, usually at a low temperature, to achieve partial sterilization or to change the physical properties of the material. This method is often utilized for substances that are heat-sensitive.

## Why the Correct Answer is Right
The correct answer, which involves the use of inspissation for sterilizing or preserving materials, is closely related to the preparation of **egg-based media**, such as **Löwenstein-Jensen medium**, which is used for culturing *Mycobacterium tuberculosis*. Inspissation at 80-85°C for 30 minutes coagulates the egg, making it a solid medium that supports the growth of certain bacteria while providing a sterile environment.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because inspissation is specifically used for materials that cannot withstand high temperatures, making it less likely to be used for general sterilization purposes that require higher temperatures.
- **Option B:** This option might seem plausible but is incorrect because inspissation is not primarily used for fixing tissues; fixation is a process usually achieved through other chemical means like formaldehyde.
- **Option C:** This option might relate to certain preservation techniques but is not directly relevant to the primary use of inspissation.

## Clinical Pearl / High-Yield Fact
A key point to remember is that inspissation is crucial for preparing **Löwenstein-Jensen medium**, which is specifically used for the isolation and cultivation of *Mycobacterium tuberculosis*. This method allows for the growth of this bacterium in a laboratory setting, aiding in diagnosis.

## Correct Answer Line
**Correct Answer: D.**