News from the Bench

Discover what’s going on at CST, receive our latest application notes and tips, read our science features, and learn about our products.


Antibody Guarantee

CST Antibody Performance Guarantee


To Purchase # 14703S

14703S 10 mg $99.00


Find answers on our FAQs page.


PhosphoSitePlus® Resource

  • Additional protein information
  • Analytical tools


Western blot analysis of extracts from NK-92 cells, serum-starved overnight and untreated (-) or treated with Human Interleukin-2 (hIL-2) #8907 (10 ng/ml, 15 min; +), either with or without Tofacitinib pretreatment (1 hr) at the indicated concentrations, using Phospho-Jak3 (Tyr980/981) (D44E3) Rabbit mAb #5031, Jak3 (D1H3) Rabbit mAb #8827, Phospho-Stat3 (Tyr705) (D3A7) XP® Rabbit mAb #9145, Stat3 (79D7) Rabbit mAb #4904, and β-Actin (D6A8) Rabbit mAb #8457.

Learn more about how we get our images

Chemical structure of Tofacitinib.

Learn more about how we get our images

Product Usage Information

Tofacitinib is supplied as a lyophilized powder. For a 50 mM stock, reconstitute the 10 mg of powder in 640.27 of μl DMSO. Working concentrations and length of treatment can vary depending on the desired effect, but it is typically used at 5-500 nM for 1-72 hr.

Solubility: Soluble in DMSO and ethanol at 100 mg/ml. Very poorly soluble in water.

Storage: Store lyophilized or in solution at -20ºC, desiccated. In lyophilized form, the chemical is stable for 24 months. Once in solution, use within 3 months to prevent loss of potency. Aliquot to avoid multiple freeze/thaw cycles.

Product Description

Molecular Weight:

312.37 g/mol



Molecular Formula:


Tofacitinib is a cell permeable Janus kinase (JAK) inhibitor with demonstrated preference to inhibiting JAK1 and JAK3 (1). Tofacitinib inhibits JAK isoforms 1, 2, and 3 with IC50 values of 6.1, 12, and 8.0 nM, respectively; the reported IC50 value relative to Tyk2 is 176 nM (2). Research studies show that tofacitinib primarily blocks γc cytokine receptors and inhibits cytokine production, which suggests that tofacitinib blocks cytokine action during both innate and adaptive responses (1,3). The overall effect of tofacitinib is to reduce inflammatory responses through selective inhibition of JAK family members (4).

1.  Ghoreschi, K. et al. (2011) J Immunol 186, 4234-43.

2.  Haan, C. et al. (2011) Chem Biol 18, 314-23.

3.  Ju, W. et al. (2011) Blood 117, 1938-46.

4.  Changelian, P.S. et al. (2003) Science 302, 875-8.

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
XP is a registered trademark of Cell Signaling Technology, Inc.