Hu Recom Flt3/Flk-2 Ligand, ACF, 1000 µg

A hematopoietic cytokine offered by STEMCELL Technologies in an animal component-free formulation, Flt3/Flk-2 (Fms-like tyrosine kinase 3/fetal liver kinase-2) Ligand acts as a co-stimulatory factor in the proliferation, differentiation, and survival of hematopoietic stem and progenitor cells and the development of the immune system. It is commonly used alongside stem cell factor and thrombopoietin to promote expansion of primitive CD34+ hematopoietic cells in culture. In combination with myeloid cytokines such as GM-CSF, G-CSF, or M-CSF, it enhances the growth and numbers of clonogenic myeloid progenitor cells. In synergy with IL-3, IL-4, IL-7, IL-11, IL-12, IL-15, GM-CSF, and TNF-α, Flt3/Flk-2 Ligand regulates the development of lymphoid progenitor cells, including dendritic cell, B cell, T cell, and NK cell progenitors. It has no significant effect on erythropoiesis or megakaryopoiesis. Both membrane-bound and soluble isoforms are biologically active and signal through the class III tyrosine kinase receptor Flt3/Flk-2 (CD135). The cytokine is produced by uncommitted and committed hematopoietic cells and stromal fibroblasts, while the receptor is expressed on CD34+ hematopoietic stem and progenitor cells, leukemic cells, and in the brain, placenta, and testis.

Expressed in E. coli and purified to ≥ 95%, the protein is lyophilized from a sterile-filtered solution containing sodium phosphate and sodium chloride, pH 7.5. The predicted molecular mass is 17.6 kDa, the accession number is P49771, and cross-reactivity is reported for mouse, rat, and monkey. Specific activity is ≥ 1 x 10^5 units/mg (EC50 ≤ 10 ng/mL), determined by cell proliferation using OCI-AML5 cells. Endotoxin level is ≤ 1 EU/μg protein by kinetic LAL analysis. The product is stored at -20°C to -80°C and is stable as supplied for 12 months from date of receipt.