Q9HBE4

The sequence of the first five N-terminal amino acids was determined and was found to be Gln-Gly-Gln-Asp-Arg.

The ED50=1-10ng/ml corresponding to a Specific Activity of 0.1-1MIU/mg , determined by the dose-dependant proliferation of human peripheral blood mononuclear cells.

Lyophilized from a concentrated (1mg/ml) solution containing no additives.

Sterile Filtered White lyophilized (freeze-dried) powder.

Protein quantitation was carried out by two independent methods1. UV spectroscopy at 280 nm using the absorbency value of 0.54 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics).
2. Analysis by RP-HPLC, using a standard solution of IL-21 as a Reference Standard.

Greater than 95.0% as determined by(a) Analysis by RP-HPLC.
(b) Analysis by SDS-PAGE.

It is recommended to reconstitute the lyophilized Interleukin -21 in sterile 18MΩ-cm H2O not less than 100ug/ml, which can then be further diluted to other aqueous solutions.

Escherichia Coli.

Lyophilized Interleukin-21 although stable at room temperature for 3 weeks, should be stored desiccated below -18^oC. Upon reconstitution IL21 should be stored at 4^oC between 2-7 days and for future use below -18^oC.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please avoid multiple freeze-thaw cycles.

Za11, IL-21.