Hu Recom LIF, ACF, 1000 µg

From STEMCELL Technologies, this animal component-free preparation of Leukemia Inhibitory Factor (LIF) is a recombinant human cytokine of the interleukin 6 class, also referred to by alternative names including CDF, D Factor, DIA, Emfilermin, HILDA, and MLPLI. Upon binding to the LIF receptor (LIFR), LIFR associates with gp130 to activate JAK/STAT and MAPK signaling, and LIFR-driven STAT3 activation is reported to be essential for maintaining the mouse embryonic stem cell phenotype. According to the manufacturer, LIF is produced by the endometrium and plays a role in implantation by regulating proliferation, invasion, and differentiation of trophoblasts after blastocyst attachment. LIF is also reported to be produced by CD4+ and activated regulatory T cells, where it promotes Foxp3 expression while repressing Th17 lineage-specific genes, and is secreted by mesenchymal stromal cells where it supports hematopoiesis and immune modulation.

The recombinant protein is expressed in E. coli and supplied lyophilized from a sterile-filtered aqueous solution containing 0.1% trifluoroacetic acid; it is reconstituted in 10 mM acetic acid to at least 0.1 mg/mL. The product has a predicted molecular mass of 19.8 kDa (UniProt accession P15018), is ≥ 95% pure by SDS-PAGE, and shows cross-reactivity with mouse. Specific activity is stated as ≥ 5.0 x 10^6 units/mg, with an EC50 of ≤ 0.2 ng/mL as determined by proliferation of TF-1 cells; the manufacturer reports an example EC50 of 0.06 ng/mL. Endotoxin is measured at ≤ 1 EU/μg protein by kinetic Limulus amebocyte lysate (LAL) analysis. Recommended storage is -20°C to -80°C, and the product is stated to remain stable for 12 months from the date of receipt when supplied.

According to the supplied safety data sheet, the preparation is not classified as hazardous under the 2012 OSHA Hazard Communication Standard (29 CFR 1910.1200) and is not a hazardous substance or mixture according to the Globally Harmonized System (GHS). The product appears as a solid. STEMCELL Technologies states that the product is for research use only and is not intended for human or animal diagnostic or therapeutic use.