Sample of spinal cord preserved in:
**Core Concept**
The correct answer lies in understanding the process of preserving tissue samples, specifically the spinal cord, for histopathological examination. This involves selecting a fixative that can effectively preserve the delicate tissue structure and prevent autolysis.
**Why the Correct Answer is Right**
The correct answer is formalin, a 10% solution of formaldehyde in water. Formalin acts as a cross-linking agent, which helps to preserve the tissue structure by covalently bonding with the proteins and other molecules in the tissue. This prevents the breakdown of cellular components and maintains the tissue morphology, making it ideal for histopathological examination. Formalin is the most commonly used fixative in pathology labs due to its effectiveness in preserving tissue samples.
**Why Each Wrong Option is Incorrect**
**Option A:** Glutaraldehyde is a fixative used for electron microscopy, but it is not suitable for routine histopathological examination of the spinal cord.
**Option B:** Acetic acid is a fixative used for preserving histological sections, but it is not the primary fixative used for preserving the spinal cord.
**Option C:** Ethanol is a dehydrating agent used in the histological processing of tissue samples, but it is not a fixative.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the choice of fixative can affect the interpretation of histopathological results. Formalin is the gold standard for preserving tissue samples, but other fixatives may be used in specific situations, such as electron microscopy or immunohistochemistry.
**Correct Answer:**. Formalin