Recombinant Human IDO Protein, CF


There are currently no images for Indoleamine 2,3-dioxygenase/IDO (6030-AO).

Every product we sell is backed by Novus' 100% Guarantee. If you have used this product, please submit your images and reviews to earn reward points.

Product Details

Reactivity HuSpecies Glossary
Applications Enzyme Activity

Order Details

Recombinant Human IDO Protein, CF Summary

Additional Information
Indoleamine 2,3-dioxygenase
Details of Functionality
Measured by its ability to oxidize L-tryptophan to N-formyl-kynurenine. The specific activity is >500 pmol/min/μg, as measured under the described conditions.
E. coli-derived human Indoleamine 2,3-dioxygenase/IDO protein
Accession # P14902
Accession #
N-terminal Sequence
Structure / Form
Protein/Peptide Type
Recombinant Enzymes
>95%, by SDS-PAGE under reducing conditions and visualized by silver stain.
Endotoxin Note
<0.10 EU per 1 μg of the protein by the LAL method.


Theoretical MW
46 kDa.
Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
42 kDa, reducing conditions
Read Publication using
6030-AO in the following applications:

Packaging, Storage & Formulations

Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 6 months from date of receipt, -70 °C as supplied.
  • 3 months, -70 °C under sterile conditions after opening.
Supplied as a 0.2 μm filtered solution in Sodium Acetate, NaCl and Glycerol.
>95%, by SDS-PAGE under reducing conditions and visualized by silver stain.
Assay Procedure
  • Assay Buffer: 50 mM MES, pH 6.5
  • 0.405 M Tris, pH 8.0
  • Recombinant Human Indoleamine 2,3‑dioxygenase/IDO (rhIDO) (Catalog # 6030-AO)
  • Ascorbic Acid (Sigma, Catalog # 255564), 500 mM stock in deionized water
  • L-Tryptophan (Sigma, Catalog # T0254), 10 mM stock in deionized water
  • Catalase (Sigma, Catalog # C30), 100,000 units/mL stock in Assay Buffer
  • Methylene Blue (Sigma, Catalog # 28514), 10 mM stock in deionized water
  • 96-well Clear Plate (Costar, Catalog # 92592)
  • Plate Reader (Model: SpectraMax Plus by Molecular Devices) or equivalent
  1. Prepare the Substrate Mixture.
    1. Dilute Ascorbic Acid to 80 mM in 0.405 M Tris, pH 8.0.
    2. Prepare a mixture of 800 μM L-Tryptophan, 9000 units/mL catalase, and 40 μM Methyene Blue in Assay Buffer.
    3. Mix equal volumes of 1a and 1b for final concentrations of 40 mM Ascorbic Acid, 400 μM L-Tryptophan, 4500 units/mL Catalase, and 20 μM Methylene Blue.
  2. Dilute rhIDO to 16 ng/μL in Assay Buffer.
  3. Load into a plate 50 μL of 16 ng/μL rhIDO, and start the reaction by adding 50 μL of Substrate Mixture.
  4. Include a Substrate Blank containing 50 μL of Assay Buffer and 50 μL of Substrate Mixture.
  5. Read at 321 nm in kinetic mode for 5 minutes.

     Specific Activity (pmol/min/µg) =

Adjusted Vmax* (OD/min) x well volume (L) x 1012 pmol/mol
ext. coeff** (M-1cm-1) x path corr.*** (cm) x amount of enzyme (µg)

     *Adjusted for Substrate Blank 
     **Using the extinction coefficient 3750 M-1cm-1 
     ***Using the path correction 0.32 cm
     Note: the output of many spectrophotometers is in mOD. Per Well:
  • rhIDO: 0.800 µg
  • Ascorbic Acid: 20 mM
  • L-Tryptophan: 200 μM
  • Catalase: 225 units
  • Methylene Blue: 10 µM


This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human IDO Protein, CF

  • 3dioxygenase
  • EC
  • IDO
  • IDO1
  • IDOIDO-1
  • INDO
  • INDOindole 2,3-dioxygenase
  • Indoleamine 2
  • indoleamine 2,3-dioxygenase 1
  • Indoleamine 2,3-dioxygenase
  • indoleamine-pyrrole 2,3 dioxygenase
  • Indoleamine-pyrrole 2,3-dioxygenase


Indoleamine 2,3-dioxygenase (IDO) is a heme-containing intracellular dioxygenase catalyzing the degradation of the essential amino acid L-tryptophan to N‑formyl‑kynurenine (1). This degradation is the first and rate-limiting step of the L-kynurenine pathway (2). IDO is widely expressed in dendritic cells, macrophages, microglia, eosinophils, fibroblasts, endothelial cells, and most tumor cells. In immune cells, its expression is mainly induced by cytokines such as IFN‑ gamma, IFN‑ alpha, IFN‑ beta, and IL‑10. IDO has an antimicrobial function due to its decreasing the availability of the essential amino acid tryptophan in inflammatory environments (3). Recent studies have demonstrated that IDO induces immunosuppression during infection, pregnancy, transplantation, autoimmunity, and neoplasia (3‑5).
  1. Lewis-Ballester, A. et al. (2009) Proc. Natl. Acad. Sci. USA. 106:17371.
  2. Costantino, G. (2009) Expert Opin. Ther. Targets 13:247.
  3. Xu, H. et al. (2008) Immunol. Lett. 121:1.
  4. Lob, S. et al. (2009) Nat. Rev. Cancer 9:445.
  5. Curti, A. et al. (2009) Blood 113:2394.

Customers Who Viewed This Item Also Viewed...

Species: Hu, Mu
Applications: WB, ICC/IF, IHC, IHC-P
Species: Hu, Mu, Rt, Po
Applications: WB, Flow, IB, ICC/IF, IHC, IHC-P, In vitro
Species: Hu, Mu, Rt, Po, Bv, Eq
Applications: WB, ICC/IF, IHC
Species: Hu, Mu, Rt, Ca, Rb
Applications: WB, Simple Western, Flow, ICC/IF, IHC, IHC-Fr, IHC-P
Species: Hu, Mu, Rt
Applications: WB, Flow, ICC/IF
Species: Hu, Mu, Rt, Bv
Applications: WB, Flow, IB, ICC/IF, IHC, IHC-P, IP, Single-Cell Western
Species: Hu, Mu
Applications: WB, ICC/IF, IHC, IHC-P
Species: Hu, Mu
Applications: WB, ICC/IF, IHC, IHC-P
Species: Hu
Applications: WB, IHC, IHC-Fr, PEP-ELISA
Species: Hu, Mu, Rt
Applications: WB, Simple Western, IHC, IHC-Fr, IHC-P
Species: Hu, Mu
Applications: WB, Flow, ICC/IF, IHC, IHC-Fr, IHC-P, IP, Flow-IC
Species: Hu, Mu, Bv, Ca, Eq, Pm
Applications: WB, IHC, IHC-P
Species: Hu, Po
Applications: Flow, ICC/IF, IF
Species: Hu
Applications: Enzyme Activity

Publications for Indoleamine 2,3-dioxygenase/IDO (6030-AO)(1)

We have publications tested in 1 confirmed species: Human.

We have publications tested in 1 application: Bioassay.

Filter By Application
All Applications
Filter By Species
All Species

Reviews for Indoleamine 2,3-dioxygenase/IDO (6030-AO) (0)

There are no reviews for Indoleamine 2,3-dioxygenase/IDO (6030-AO). By submitting a review you will receive an Amazon e-Gift Card or Novus Product Discount.
  • Review with no image -- $10/€7/£6/$10 CAD/¥70 Yuan/¥1110 Yen
  • Review with an image -- $25/€18/£15/$25 CAD/¥150 Yuan/¥2500 Yen

FAQs for Indoleamine 2,3-dioxygenase/IDO (6030-AO) (0)

There are no specific FAQs related to this product. Read our general customer & technical service FAQs.

Other Available Formats

Additional Indoleamine 2,3-dioxygenase/IDO Products

Bioinformatics Tool for Indoleamine 2,3-dioxygenase/IDO (6030-AO)

Discover related pathways, diseases and genes to Indoleamine 2,3-dioxygenase/IDO (6030-AO). Need help? Read the Bioinformatics Tool Guide for instructions on using this tool.
Visit Tool

Diseases for Indoleamine 2,3-dioxygenase/IDO (6030-AO)

Discover more about diseases related to Indoleamine 2,3-dioxygenase/IDO (6030-AO).

Pathways for Indoleamine 2,3-dioxygenase/IDO (6030-AO)

View related products by pathway.

PTMs for Indoleamine 2,3-dioxygenase/IDO (6030-AO)

Learn more about PTMs related to Indoleamine 2,3-dioxygenase/IDO (6030-AO).

Blogs on Indoleamine 2,3-dioxygenase/IDO

There are no specific blogs for Indoleamine 2,3-dioxygenase/IDO, but you can read our latest blog posts.

Customers Who Bought This Also Bought

Contact Information

Product PDFs


Concentration Calculator

The concentration calculator allows you to quickly calculate the volume, mass or concentration of your vial. Simply enter your mass, volume, or concentration values for your reagent and the calculator will determine the rest.


Review this Product

Be the first to review our Recombinant Human IDO Protein, CF and receive a gift card or discount.


Gene Symbol IDO1