What does "acidophilic" pertain to?

"Acidophilic" refers to cells or substances that have an affinity for acid stains, meaning they take up and retain acidic dyes during laboratory staining procedures. This characteristic allows for better visualization of certain cells under a microscope, as they will appear more prominently against the background. Acidophilic cells, such as certain types of eosinophils and some epithelial cells, typically contain proteins or structures that bind readily to these acidic dyes.

The term combines "acido-" indicating acid, and "-philic," which implies a love or affinity for something. In histology, this property is crucial for identifying and studying various types of cells, particularly in tissue samples, where distinguishing among different cellular components is necessary for diagnosis and research.