Tissue histology is tissue morphology. This means that a histologist will examine all tissue samples grossly. All tissue has a definite “normal” appearance as seen inside and outside its normal environment. This tissue must be described as color, shape, and size before it can be processed for microscopic evaluation. This description (morphology) is part of the tissue histology. The second part is the microscopic description (morphology) of the tissue after it has been stained. The typical stain done on all tissues is the hematoxylin and eosin (H&E). This shows the basic structure of the tissue. All tissue components that are basophilic are stained with eosin and will have a pink hue. All the tissue components that are acidophilic are stained purplish blue with the hematoxylin. These are typically the nuclei that turn blue. This stain allows the identification of a particular tissue type, (muscle, lung, and so on). The examination and description of the microscopic structures constitutes the tissue histology.