Recombinant Human LIF
Leukemia Inhibitory Factor (LIF) is a lymphoid factor that promotes long-term maintenance of pluripotent embryonic stem cells by suppressing spontaneous differentiation. Recombinant Human Leukemia inhibitory factor (hLIF) is produced in E. coli. It contains a single non-glycosylated polypeptide chain 181 amino acids and has a molecular mass of 20kDa. hLIF is purified by proprietary techniques using HPLC and FPLC chromatography.
SDS PAGE of hLIF Sample
Source
Escherichia Coli.
Purity
Greater than 95%, as determined by SDS-PAGE (See Fig. 1)
Endotoxin
Less than 0.01 ng/µg cytokine as determined by the LAL assay
Bioactivity
The activity of human LIF was tested by the M1 cell differentiation assay. Specific activity of the sample is approximate 108 units/mg. 0.5x107 units, identical 50 µg of pure protein, are sufficient to treat 5.0 L of stem cells including human embryonic stem cells, neural stem cells, hematopoietic stem cells, mesenchymal stem cells and induced pluripotent stem cells.
Formulation
0.22 µm filtered sterile liquid, phosphate-buffered saline with 0.02% Tween-20 and 1% BSA.
Storage
Maintain at 4°C for 18 months. Freeze-thaw should be avoided as it results in loss of activity.