Flt3-ligand, human, recombinant




Fms-related tyrosine kinase 3 ligand, Flt3L


Flt3-ligand (FMS related tyrosine kinase 3 ligand, flk-2 ligand) is involved in proliferation and differentiation of early hematopietic cells. Flt3-ligand synergizes with other CSF’s and interleukins to induce proliferation of early hematopoietic cells, but does not stimulate growth or differentation alone. Flt3-ligand binds to cells expressing the tyrosine kinase receptor Flt3. Multiple isoforms of Flt3-ligand have been identified but the predominant biologically active isoform is a transmembrane protein which can be proteolytically cleaved to generate a biologically active soluble form. 


Produced in the endosperm tissue of barley grain (Hordeum vulgare).


Sterile filtered through a 0.2 µm filter. Lyophilized from PBS, pH 7.2 


Greater than 95% by SDS-PAGE gel analysis.


Note: Always centrifuge the vial before opening.  It is recommended to reconstitute the lyophilized protein in sterile water to a concentration of no less than 100 µg/ml.  For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).


The lyophilized protein, though stable at room temperature for few weeks, is best stored at -20°C. Reconstituted protein should be used immediately or stored in working aliquots at -20°C. Avoid repeated freeze-thaw cycles.


Each batch of ISOkine™ growth factor is tested for bioactivity and verified to have comparable activity to a commercial source. The bioactivity of ISOkine™ recombinant human Flt-3 ligand was determined by its dose-dependent effects on the proliferation of AML5 cells. The ED50 value for this ISOkine™ is typically < 0.3 ng/ml corresponding to specific activity > 3.3 x 10e6 U/mg. Optimal concentration should be determined for specific applications and cell lines. 


Endotoxin level is less than 0.005ng per µg of ISOkine™ product (<0.05EU/µg).

MAT assay

Purified ISOkine™ product carries no pyrogenic or pro-inflammatory contaminants, as assayed with monocyte activation test using Human 10-plex Cytokine Assay measuring IL-6, TNF-alpha and IL-1beta induction. Ref. The Blood Bank, University Hospital of Iceland, Reykjavik, Iceland 


Recombinant human Flt3-ligand contains 156 amino acids and a 16 a.a. Histidine-based tag for a total length of 172  a.a. and has a predicted molecular mass of 19.9 kDa. As a result of glycosylation, the recombinant protein migrates as two bands with an apparent molecular mass of 20 and 22 kDa in SDS-PAGE.

Regular price €128