The purpose of immunohistochemistry after biopsy is to determine the general source of the submitted specimen, the direction of tumor differentiation, and the degree of differentiation. Immunohistochemical markers related to clinical treatment prognosis are used for some tumor patients to help clinicians with further diagnosis and treatment for patients.
1. Specimens used in experiments are mainly divided into two categories: tissue specimens and cell specimens. The former includes paraffin sections (pathological sections and tissue chips) and frozen sections, while the latter includes tissue impressions, cell crawls, and cell smears. Among them, paraffin sections are the most commonly used and basic method for making tissue specimens. They are good for preserving tissue morphology and can be used for continuous sectioning, which is beneficial for various staining control observations. They can also be archived for long-term retrospective research. Although the production process of paraffin sections has a certain impact on the exposure of antigens within the tissue, antigen repair can be performed, making it the preferred method for making tissue specimens in immunohistochemistry.
2. Antibodies commonly used in antibody immunohistochemical experiments include monoclonal antibodies and polyclonal antibodies. Monoclonal antibodies are antibodies secreted by a B lymphocyte clone, which are prepared by immunizing animals using cell fusion hybridoma technology. Polyclonal antibodies are immune sera obtained from animal blood after directly immunizing animals with purified antigens. They are mixtures of antibodies produced by multiple B lymphocyte clones.
3. Common staining methods are divided into immunofluorescence, immunoenzyme labeling, and affinity histochemistry based on different labels. Affinity histochemistry is a detection method based on the high affinity of a substance to a certain tissue component. This method has higher sensitivity and is beneficial for the localization of trace antigens (antibodies) at the cellular or subcellular level. Among them, the biotin-avidin staining method is the most commonly used.
