Hu Recom Flt3/Flk-2 Ligand, 100 µg

STEMCELL Technologies supplies Human Recombinant Flt3/Flk-2 Ligand expressed in E. coli as a hematopoietic cytokine, also referred to as Fms-like tyrosine kinase 3/fetal liver kinase-2 (alternative names: FL, FLT3L, Flt3-L, Flt3 Ligand). The protein (UniProt accession P49771) has a predicted molecular mass of 17.6 kDa and is supplied lyophilized from a sterile-filtered solution containing sodium phosphate and sodium chloride at pH 7.5.

The ligand functions as a co-stimulatory factor supporting proliferation, differentiation, and survival of hematopoietic stem and progenitor cells, and contributes to immune system development. It is commonly used alongside stem cell factor and thrombopoietin to expand primitive CD34+ hematopoietic cells in culture, and 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, it supports the development of lymphoid progenitors including dendritic, B, T, and NK cell lineages, while showing no significant effect on erythropoiesis or megakaryopoiesis. Both membrane-bound and soluble isoforms exist, and both are biologically active through the class III tyrosine kinase receptor CD135.

Reported purity is ≥ 97%, with a specific activity of ≥ 2 x 10^5 units/mg determined by a cell proliferation assay using OCI-AML5 cells, corresponding to an EC50 ≤ 5 ng/mL. Endotoxin level is ≤ 0.1 EU/μg protein as measured by kinetic LAL analysis. Store at -20 to -80°C; stable as supplied for 12 months from the date of receipt. Centrifuge the vial before opening and reconstitute in sterile water to at least 0.1 mg/mL by pipetting the solution down the sides of the vial; do not vortex. After reconstitution, optional dilution with concentrated bovine serum albumin to a final concentration of 0.1% may be applied if the product will not be used immediately. For research use only; not intended for human or animal diagnostic or therapeutic uses.