Human Interleukin 4 (Active)

Recombinant human IL-4 produced in Escherichia coli as a biologically active, non-glycosylated single-chain cytokine of approximately 15 kDa. This unconjugated, lyophilized preparation from Antibodies.com is supplied at 10 µg per vial and supports Th2 lymphocyte polarization, B-cell class-switch recombination toward IgE and IgG1, and mast cell proliferation in cell culture and in vitro immunology workflows. After reconstitution in sterile deionized water or assay buffer, the protein remains stable for short-term use at 4 °C and should be stored at -20 °C for long-term retention of bioactivity; aliquot to limit freeze-thaw cycles. Functional activity is commonly validated using an IL-4-dependent proliferation readout such as the TF-1 human erythroleukemia cell line, with specific activity typically exceeding 1 × 10⁷ units/mg. Intended for research use only in studies of cytokine signaling, allergic inflammation, IgE regulation, and hematopoietic differentiation.