IL4, also known as Interleukin 4 isoform1, is a pleiotropic cytokine that has many biological roles, including the stimulation of activated B-cell and T-cell proliferation, and the differentiation of naive helper T-cell to Th2 cells. IL4 is a co-stimulator of DNA-synthesis and is induces the expression of class II MHC molecules on resting B-cells. It also enhances both secretion and cell surface expression of IgE and IgG1. Source: Recombinant protein corresponding to aa25-153 from mouse IL4, expressed in E. coli. Molecular Weight: ~15kD (130aa) Amino Acid Sequence: MHKCDITLQE IIKTLNSLTE QKTLCTELTV TDIFAASKNT TEKETFCRAA TVLRQFYSHH EKDTRCLGAT AQQFHRHKQL IRFLKRLDRN LWGLAGLNSC PVKEANQSTL ENFLERLKTI MREKYSKCSS Endotoxin: ~1EU/1ug (LAL) Biological Activity: Measured in a cell proliferation assay using TF1 human erythroleukemic cells. The ED50 for this effect is 0.6ng/ml. Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.