Interleukin 21 (IL-21) is a T cell-derived pleiotropic cytokine that has potent regulatory effects on cells of the immune system, including natural killer (NK) cells and cytotoxic T cells that can destroy virally infected or cancerous cells.1,2 This cytokine induces cell division/proliferation in its target cells. IL-21 elicits its effects on immune cells by interacting with a cell surface receptor known as the interleukin 21 receptor, IL-21R, which is expressed in bone marrow cells and various lymphocytes. IL-21 is closely related to IL-2 and IL-153 and is a key factor in the transition between innate and adaptive immune responses.4 The critical role of IL21 in promoting humoral immune responses makes it an important focus of potential therapeutic interventions in conditions characterised by overproduction of pathogenic autoantibodies.5
>95% by SDS Page and analyzed by silver stain.
<1.0 EU/µg as determined by the LAL method
The biological activity of Human IL-21 was determined determined by the dose-dependant stimulation of human peripheral blood mononuclear cells. The expected ED50 is <5 ng/ml.
Protein Accession No.
Amino Acid Sequence
MQDRHMIRMR QLIDIVDQLK NYVNDLVPEF LPAPEDVETN CEWSAFSCFQ KAQLKSANTG NNERIINVSI KKLKRKPPST NAGRRQKHRL TCPSCDSYEK KPPKEFLERF KSLLQKMIHQ HLSSRTHGSE DS
State of Matter
Predicted Molecular Mass
The molecular weight of Recombinant Human IL-21 is Mr 15.4 kDa.
This recombinant protein was 0.2 µm filtered and lyophilized from modified Dulbecco’s phosphate buffered saline (1X PBS) pH 7.2 – 7.3 with no calcium, magnesium, or preservatives.
Storage and Stability
This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.
Country of Origin
Next Day Ambient
NCBI Gene Bank
References & Citations
1. Foster D et al. (2000) Nature 408: 57 2. Clegg CH et al. (2002) J. Leukoc. Biol. 72: 856 3. Leonard WJ.et al. (2002) Science 298: 1630 4. Joannopoulos K.et al. (2003) J. Immunol. 171: 608 5. Lipsky PE. et al. (2008) Ann Rheum. Dis. 3: 83
IMPORTANT Use lot specific datasheet for all technical information pertaining to this recombinant protein.
Products are for research use only. Not for use in diagnostic or therapeutic procedures.