Topic summary
Histochemistry

Extracted from the Wikipedia article Immunohistochemistry.
Diagnostic immunohistochemistry markers
Immunohistochemistry is an excellent detection technique and has the tremendous advantage of being able to show exactly where a given protein is located within the tissue examined. It is also an effective way to examine the tissues. This has made it a widely used technique in neuroscience, enabling researchers to examine protein expression within specific brain structures. Its major disadvantage is that, unlike immunoblotting techniques where staining is checked against a molecular weight ladder, it is impossible to show in immunohistochemistry that the staining corresponds with the protein of interest. For this reason, primary antibodies must be well-validated in a Western Blot or similar procedure. The technique is even more widely used in diagnostic surgical pathology for immunophenotyping tumors (e.g. immunostaining for e-cadherin to differentiate between ductal carcinoma in situ (stains positive) and lobular carcinoma in situ (does not stain positive)). More recently, immunohistochemical techniques have been useful in differential diagnoses of multiple forms of salivary gland, head, and neck carcinomas.