immunohistochemistry

Standard histological staining

The morphological structure of tissue can be depicted with high accuracy by means of histological sections. Staining results depend on numerous factors, including pH of the buffer solution, staining time and method of fixation. Haematoxylin, for example, is used to stain cell and tissue structures, such as cell nuclei, mitochondria, myelin, elastin and collagen fibres. Additional information may be obtained from counterstaining (differential staining), using a dyestuff in high contrast to hematoxylin stain. Counterstaining, using eosin, is a classical approach for which cationic structures are stained (e.g. proteins).

Immunohistochemical staining

Identification of antisera, immunoglobulin fractions and monoclonal antibodies to a growing number of clinically relevant tissue antigens has led to an enormous enlargement of immunohistochemical analyses in both quality and quantity. Antibody titre and dilution as well as incubation time and temperature are closely linked to each other with regard to their influence on the quality of immunohistochemical staining. These factors are varied either separately of each other or each of them in itself to achieve clearly recordable differences in staining quality. Parameters are varied primarily for the purpose of accomplishing staining of optimum specificity against minimum background.