Histological

Histological refers to histology, the branch of anatomy and biology that studies the microscopic structure of tissues. Histological analysis aims to understand the organization of cells within tissues, their relationships, and how this organization underlies function. The field underpins medical diagnosis and biological research, as many diseases manifest changes at the tissue level that are visible only under the microscope.

Preparation of histological samples typically involves fixation to preserve structure, embedding in a support such as paraffin, and cutting thin sections with a microtome. Sections are mounted on slides and stained to reveal different components. The most common stain is hematoxylin and eosin (H&E), which highlights nuclei in blue and cytoplasm and fibers in pink. Additional staining techniques include special stains for connective tissue, lipids, or carbohydrates, and immunohistochemistry, which uses antibodies to detect specific proteins. In situ hybridization detects nucleic acids.

Histological examination is central to histopathology, the study of disease in tissues. Pathologists evaluate the architecture, cell morphology, and staining patterns to diagnose conditions such as cancers, inflammatory diseases, and degenerative disorders. Histology is also used in basic research to study development, organ function, and tissue remodeling.

Limitations include potential artifacts from preparation, sampling bias, and the fact that two-dimensional sections may not capture three-dimensional structures. Advances in digital pathology, whole-slide imaging, and image analysis enable quantitative assessment and remote consultation. Safety considerations include handling fixatives and stains in properly equipped laboratories.