Anti-IL21 Polyclonal Antibody for WB, IF/ICC, IHC-P, ELISA - Q9HBE4

Core Product Specifications and Parameters

Biological Background: IL21 Function and Localization

• Interleukin-21 (IL-21), encoded by the IL21 gene, is a cytokine with immunoregulatory functions, also known as Za11.
• Promotes the transition between innate and adaptive immunity and induces the production of IgG1 and IgG3 in B-cells (By similarity).
• Implicated in the generation and maintenance of T follicular helper (Tfh) cells and the formation of germinal centers; together with IL-6, controls early Tfh cell generation and is critical for effective antibody responses to acute viral infections (By similarity).
• May enhance proliferation and maturation of natural killer (NK) cells in synergy with IL-15, and regulate proliferation of mature B- and T-cells in response to activating stimuli.
• In synergy with IL-15 and IL-18, stimulates interferon gamma production in T-cells and NK cells. Related references: PMID:11081504 PMID:15178704
• During T-cell-mediated immune responses, may inhibit dendritic cell (DC) activation and maturation (By similarity).
• Secreted protein expressed specifically in activated CD4-positive T-cells, but not in CD8-positive T-cells, B-cells, or monocytes.
• Contains disulfide bonds and is glycosylated; alternative splicing produces multiple isoforms; associated with common variable immunodeficiency (CVID11).

Experimental Guidance and Technical Tips

• The immunogen corresponds to amino acids 25-162 of human IL-21, a region covering the mature cytokine; confirm sequence conservation across species (human, mouse, rat) for expected cross-reactivity.
• For Western blotting, the predicted molecular weight is 19 kDa; be aware that glycosylation may cause a shift in migration. Validate in a relevant sample system.
• In immunofluorescence/ICC and IHC-P, consider using appropriate fixation and permeabilization conditions for detection of secreted cytokines; include positive controls such as activated T-cells.
• For ELISA applications, validate the antibody pair suitability with recombinant protein standards to ensure sensitivity and specificity.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio connects diagnostic manufacturers and research laboratories with a comprehensive portfolio of IVD raw materials. This IL-21 polyclonal antibody supports immunology research into T follicular helper cells, germinal center biology, and cytokine signaling. Beyond this product, CamelBio offers validated antibody pairs, optimized monoclonal and polyclonal antibodies, bulk ancillary reagents, and expert sourcing for rare-target raw materials to streamline your assay development workflow.