Description : |
IL-4 (Interleukin 4, B cell stimulatory factor) is a pleiotropic cytokine produced by activated T cells, mast cells and basophils. IL-4 has many different functions including promoting proliferation and differentiation of immunologically competent cells. One of its main functions is regulating differentiation of naive CD4+ T cells into helper Th2 cells, the other main function is regulating B cells IgE and IgG1 production. Human IL-4 shows 50% homology with mouse IL-4, but its activities are species-specific and human IL-4 shows no activity on murine and rat cells. |
Source : |
Barley grain (Hordeum vulgare) |
Species : |
Human |
Tag : |
His |
Form : |
Sterile filtered through a 0.2 μm filter. Lyophilized from PBS, pH7,2 |
Bio-activity : |
Recombinant human IL-4 was determined by its dose-dependent effects on the proliferation of TF-1 cells. The ED50 value for this effect is typically< 0.3 ng/ml, corresponding to a specific activity>3.3 x 10e6 units/mg. Optimal concentration should be determined for specific applications and cell lines. |
Molecular Mass : |
Recombinant human IL-4 contains 130 amino acids and a 16 a.a. Histidine-based tag for a total length of 146 a.a. and has a predicted molecular mass of 17.2 kDa. Due to glycosylation the recombinant protein migrates as smeary band with an apparent molecular mass of 23 kDa in SDS-PAGE. |
Endotoxin : |
Endotoxin level is less than 0.005ng per μg of product (<> |
Purity : |
Greater than 95% by SDS-PAGE gel analysis. |
Storage : |
The lyophilized protein, though stable at room temperature for few weeks, is best stored at -20°C. Reconstituted protein should be used immediately or stored in working aliquots at -20°C. Avoid repeated freeze-thaw cycles. |
Reconstitution : |
Always centrifuge the vial before opening. It is recommended to reconstitute the lyophilized protein in sterile low salt buffer to a concentration of no less than 100 μg/ml. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). |