Thermo Scientific Pierce Biotinylated Proteins include biotin-labeled proteins (BSA), enzymes (HRP, AP) and fluorophores (FITC) for use as controls or signal amplification in IHC via avidin-biotin complex (ABC) techniques.
Biotinylated HRP and biotinylated AP are most commonly used in immunohistochemistry (IHC) to amplify the signal of biotinylated primary antibodies using the ABC staining method. Biotinylated Fluorescein (FITC) cannot be used to polymerize and amplify the signal to the same degree as biotinylated enzymes because each fluor molecule is tagged with only one biotin molecule. However, the fluorescent variant of traditional ABC staining is possible with this unique molecule.
- Biotinylated enzymes – biotin-labeled horseradish peroxidase (B-HRP), alkaline phosphatase (B-AP) and beta-galactosidase (B-bGal) for use in avidin-biotin complex (ABC) staining
- Biotinylated FITC – amplify the fluorescein signal of biotinylated primary antibodies by using avidin or streptavidin plus biotinylated fluorescein (B-FITC)
- Biotinylated controls – use biotinylated bovine serum albumin (B-BSA) or any one of these molecules as positive controls in biotin quantitation methods
Biotin, also known as vitamin H, is a small molecule (MW 244.3) that is present in tiny amounts in all living cells and is critical for a number of biological processes. The valeric acid side chain of the biotin molecule can be derivatized in order to incorporate various reactive groups that are used to attach biotin to other molecules. In the context of immunohistochemistry (IHC), biotin is conjugated to antibodies or to the enzyme reporters used to detect target antigens.
Schematic representation of the Avidin-Biotin Complex (ABC) method of signal amplification for immunohistochemical (IHC) staining.
Protein Methods Library: Avidin-Biotin Complex Method for IHC
Protein Methods Library: Overview of Protein Biotinylation
ABC Staining Kits