[Biotinylated ligands for receptor localization. An alternative for immunohistochemistry]

Immunohistochemical techniques are prerequisite for the classification and characterization of numerous diseases. The incubation with labelled ligands is an alternative to immunohistochemistry, and allows the recognition of receptors independent from their immunogenic properties. The biotinylation and immobilization of small molecules such as sugars can be performed under the conservation of active receptor-binding sites. Certain sugars bound to bovine serum albumin are highly specific markers for bronchial carcinomas and lung parenchyma altered by cytostatic drug regimes, infection or inflammation. Biotinylated growth factors such as epidermal growth factor or biotinylated hormones are useful tools for the demonstration of the corresponding receptors. These tools are called "neoligandoproteins". The number specific binding sites and the thermodynamic binding parameters can be measured with sugars bound to enzymes. The number of and the expression of specific sugar binding sites can be correlated to the differentiation and metastatic potency of malignant tumors. In addition, cytostatic drugs can be bound to carbohydrates. This technique offers new perspectives in the affinity and quantification of target-related cytostatic drug regimens.