In the micrograph, what tissue is shown and what staining is observed?

In the micrograph, what tissue is shown and what staining is observed?

• A. Hyaline cartilage with basophilic staining
• B. Hyaline cartilage with eosinophilic staining
• C. Elastic cartilage with basophilic staining
• D. Dense irregular connective tissue with basophilic staining

Answer: (A)

Focus on what the tissue looks like and how it stains. Basophilic staining means the tissue components pick up the blue/purple color from a basic dye (like hematoxylin). In cartilage, the extracellular matrix is rich in sulfated glycosaminoglycans within proteoglycans, which are negatively charged and bind the basic dye strongly. This makes the matrix appear basophilic (blue/purple) under H&E. If the micrograph shows a smooth, glassy matrix with round chondrocytes nestled in small spaces (lacunae) and no obvious bundles of collagen fibers or elastic fibers, that pattern is characteristic of hyaline cartilage. The chondrocytes may appear in isolated or small groups within that basophilic matrix, and the perichondrium may or may not be visible depending on the section. Elastic cartilage would show visible elastic fibers within the matrix, and dense irregular connective tissue would display densely packed collagen fibers with fibroblasts, not chondrocytes in lacunae. So the combination of hyaline cartilage features with basophilic matrix makes the first option the best match.

Focus on what the tissue looks like and how it stains. Basophilic staining means the tissue components pick up the blue/purple color from a basic dye (like hematoxylin). In cartilage, the extracellular matrix is rich in sulfated glycosaminoglycans within proteoglycans, which are negatively charged and bind the basic dye strongly. This makes the matrix appear basophilic (blue/purple) under H&E.

If the micrograph shows a smooth, glassy matrix with round chondrocytes nestled in small spaces (lacunae) and no obvious bundles of collagen fibers or elastic fibers, that pattern is characteristic of hyaline cartilage. The chondrocytes may appear in isolated or small groups within that basophilic matrix, and the perichondrium may or may not be visible depending on the section.

Elastic cartilage would show visible elastic fibers within the matrix, and dense irregular connective tissue would display densely packed collagen fibers with fibroblasts, not chondrocytes in lacunae. So the combination of hyaline cartilage features with basophilic matrix makes the first option the best match.