Recombinant Human IL4 was expressed in E. coli.
Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH 7.4.
Fully biologically active when compared to standard. The ED50 as determined by a cell proliferation assay using human TF-1 cells is less than 0.2 ng/ml, corresponding to a specific activity of > 5.0 × 10^6 IU/mg.
Approximately 15.0 kDa, a single non-glycosylated polypeptide chain containing 129 amino acids.
129 amino acids
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Less than 1.0 EU/µg of rHuIL-4 as determined by LAL method.
> 98 % by SDS-PAGE and HPLC analyses.
This lyophilized preparation is stable at 2-8 centigrade, but should be kept at -20 centigrade for long term storage, preferably desiccated. Upon reconstitution, the preparation is stable for up to one week at 2-8 centigrade. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20 centigrade to -70 centigrade. Avoid repeated freeze/thaw cycles.
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1 % BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 centigrade. Further dilutions should be made in appropriate buffered solutions.