Leukemia Inhibitory Factor (LIF) is a lymphoid factor which promotes long-term maintenance of embryonic stem cells by suppressing spontaneous differentiation. LIF has a number of other activities including cholinergic neuron differentiation, control of stem cell pluripotency, bone and fat metabolism, mitogenesis of certain factor dependent cell lines and promotion of megakaryocyte production in vivo. Human LIF is a 19.7kD protein containing 181aa residues. The non-glycosylated, E. coli expressed, recombinant human LIF is indistinguishable from native LIF in its biological activities in vitro. Human and murine mature LIF exhibit a 78% sequence identity at the amino acid control. Human LIF is equally active on both human and mouse cells. Murine LIF is approximately 1000 fold less active on human cells, than hLIF.
Source:Recombinant corresponding to human LIF expressed in E.coli.
Biological Activity:Determined by the ability to induce differentiation of M1 myeloid leukemic cells. The minimum detectable concentration of human LIF in this assay is 0.5ng/mL.
Specific Activity:≥1x10e8units/mg
Unit Definition:50 units is defined as the amount of human LIF required to induce differentiation in 50% of the M1 colonies in 1ml agar cultures.
Endotoxin: ~0.1ng/ug of LIF
Storage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
仕様
Size：5ug
Source Antigen：Recombinant, E.coli
Grade：Highly Purified
Purity：~95% (HPLC and SDS-PAGE)
Form：Supplied as a liquid in PBS, pH 7.4, 0.02% Tween 20. No preservatives added.
