All Photos(3)




buffered aqueous solution

MDL number:


buffered aqueous solution

Quality Level

extent of labeling

3-6 mol fluorochrome per mol protein


immunohistochemistry (formalin-fixed, paraffin-embedded sections): 20 μg/mL using human tissues
indirect immunofluorescence: 1:200


FITC conjugate

shipped in

dry ice

storage temp.


General description

Avidin is a tetrameric or dimeric biotin-binding protein produced in the oviducts of birds, reptiles and amphibians and deposited in the whites of their eggs. It consists of four high affinity binding sites for biotin. ExtrAvidin is prepared from egg white avidin. It is a modified form of affinity purified avidin and combines high specific activity of avidin with the low background staining of streptavidin. It is a biotin binding protein produced by the bacteria Streptomyces avidinii. ExtrAvidin has been conjugated to fluorescein isothiocyanate (FITC) and is used for various techniques.


ExtrAvidin®-FITC is suitable for the following applications:
  • immunohistochemistry (formalin-fixed, paraffin-embedded sections) at a concentration of 20μg/mL using human tissues.
  • Immunofluorescence†
  • competitive binding assay

Physical form

Solution in 0.01 M phosphate buffered saline, containing 10% (v/v) 0.5 M carbonate buffer, pH 9.5, and 15 mM sodium azide

Preparation Note

Affinity purified protein

Legal Information

ExtrAvidin is a registered trademark of Sigma-Aldrich Co. LLC


Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.

Storage Class Code

12 - Non Combustible Liquids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

Therapeutic monoclonal antibodies for Ebola virus infection derived from vaccinated humans
Rijal P, et al.
Cell Reports, 27, 172-186 (2019)
Dereje Getachew et al.
Congenital anomalies, 61(1), 14-24 (2020-08-11)
The apico-basal (AB) polarity of epithelial cells is maintained by organized arrays of the cytoskeleton and adhesion apparatus. We previously reported that mouse embryonic esophageal epithelium exhibits interkinetic nuclear migration (INM), an AB-polarity-based regulatory mechanism of stem-cell proliferation, and suggested...
D R Hampson et al.
The Journal of biological chemistry, 274(47), 33488-33495 (1999-11-24)
Metabotropic glutamate receptors (mGluRs) are G-protein-coupled glutamate receptors that subserve a number of diverse functions in the central nervous system. The large extracellular amino-terminal domains (ATDs) of mGluRs are homologous to the periplasmic binding proteins in bacteria. In this study...
Wan-Kun Gong et al.
Neurobiology of learning and memory, 168, 107156-107156 (2020-01-07)
Region- and pathway-specific plasticity within striatal circuits is critically involved in the acquisition and long-term retention of a new motor skill as it becomes automatized. However, the molecular substrates contributing to this plasticity remain unclear. Here, we examined the expression...
Expression and localization of urokinase-type plasminogen activator receptor in bovine cumulus--oocyte complexes
Garcia DC
Zygote, 24, 230-235 (2016)

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service