Description : |
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 megakary centigradeyte production in vivo. Mouse LIF is a 20 kDa protein containing 181 amino acid residues. |
Source : |
Hordeum vulgare |
Species : |
Mouse |
Form : |
Lyophilized . PBS, pH 7.2, sterile filtered. |
Bio-activity : |
Each batch is tested for bioactivity and verified to have comparable activity to a commercial source. The bioactivity of ISOkineTM murine LIF was determined by its ability to induce differentiation of murine M1 myeloid leukemia cells. The ED50 value for this effect is typically< 1 ng/ml, corresponding to a specific activity of>5 x 10e7 U/mg (where 50 U is defined as the amount of mLIF required to induce differentiation of 50% of M1 cells). The activity is comparable to mLIF from other commercial sources. We recommend that the optimal concentration for each specific application be determined by an initial dose-response assay. |
Molecular Mass : |
Recombinant mouse LIF contains 188 amino acids and a 16 a.a. Histidine-based tag for a total length of 204 a.a. and has a predicted molecular mass of 22.8 kDa. As a result of glycosylation, the recombinant protein migrates with an apparent molecular mass of 28-30 kDa in SDS-PAGE. |
Endotoxin : |
Endotoxin Endotoxin level is less than 0.005ng per μg(0.05EU/μg) as measured by turbidimetric kinetic assay. |
Purity : |
Greater than 95% by SDS-PAGE gel analysis |
Usage : |
FOR RESEARCH USE ONLY |
Quality Control Test : |
12 months from date of receipt, -20 to 70 centigrade as supplied. 1 month, 2 to 8 centigrade under sterile conditions after reconstitution. 3 months, -20 to 70 centigrade under sterile conditions after reconstitution. |
Reconstitution : |
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). |
Warning : |
Avoid repeated freeze-thaw cycles. |