LIF - mouse

LIF (leukemia inhibitory factor, myeloid leukemia inhibitory factor) a pleiotropic lymphoid factor was initially described as a factor that inhibits the proliferation of myeloid leukemia cells and induces their differentiation into macrophages. Other activities of LIF include inhibition of adipogenesis, cholinergic neuron differentiation and bone metabolism . Human and mouse LIF share 78% homology and activities of LIF are not species specific. Human LIF is active on mouse cells, but murine LIF is not active on human cells

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

PBS pH 7.2, sterile filtered through 0.2 µm filter.

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 phosphate buffered saline to a concentration of no less than 100 µg/ml. For long term storage of the reconstituted solution 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 murine LIF was determined by its ability to induce differentiation of murine M1 myeloid leukemia cells where 50 U is defined as the amount of mLIF required to induce differentiation of 50% of M1 cells. 10 ug of ISOkine mLIF protein is equivalent to approximately 10e6 activity units. The ISOkine mLIF has been validated in standard mESC based gene targeting for generation of knock out mice. We recommend that the optimal concentration for each specific application be determined by an initial dose response assay.

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

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 mouse LIF contains 188 amino acids and a 10 a.a. histidine based tag for a total length of 199 a.a. and has a predicted molecular mass of 21.2 kDa. As a result of glycosylation, the recombinant protein migrates with an apparent molecular mass of 28 30 kDa in SDS PAGE.