• LIF20
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Leukemia Inhibitory Factor from mouse

D Factor, Differentiation-stimulating Factor, LIF

biological source


Quality Level


>95% (SDS-PAGE)




cell culture | stem cell: suitable


<0.1 ng/mg endotoxin (of LIF)


sample type mesenchymal stem cell(s)
sample type neural stem cell(s)
sample type induced pluripotent stem cell(s)
sample type: mouse embryonic stem cell(s)
sample type hematopoietic stem cell(s)

NCBI accession no.

UniProt accession no.

General 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 megakaryocyte production in vivo. Mouse LIF is a 22 kDa protein containing 203 amino acid residues.
mLIF is expressed in E. coli as a fusion protein with GST using the pGEX expression system, cleaved from GST moeity with thrombin and purified by HPLC chromatography.


5 μg, mouse recombinant LIF protein, expressed in E. coli, suitable for stem cell culture

M1 Bioassay

1. The M1 bioassay is performed using in vitro semi-solid agar cultures, which contain approximately 100 cells in 1 mL volumes of DME containing 20 % FCS in 0.3% agar.

2. Add 100 μL of sample or mLIF (10(E4) units/mL in 5% FCS in isotonic saline) in two-fold serial dilutions in duplicate to 35 mm petri dishes.

3. Add 100 μL of 5% FCS in isotonic saline to two control slides.

4. Incubate at 37°C in fully humidified atmosphere of 10% CO2 in air for 7 days.

5. Score the number of colonies that show differentiation (note: 50 units is defined as the amount of activity which results in 50% of the colonies being differentiated).

Visit for additional information

Manufactured by CHEMICON International, Inc. LIF is protected under US Patent nos. 5,443,825, 5,750,654 and 6,261,548, European Patent no. 0285 448 and related foreign patents and is not available for resale.

Unit Definition

The specific activity is ≥1 x 10(E8) units/mg, where 50 units is defined as the amount of mouse LIF required to induce differentiation in 50% of the M1 colonies in 1 mL agar cultures.

Physical form

Liquid in PBS, pH 7.4 and 0.02% Tween 20. No preservativies added.

Storage and Stability

Maintain at 2-8°C for 6 - 12 months. Further dilutions should be made into buffer or medium to which protein (e.g., 1% BSA) or Tween 20 has been added.

Manufactured by CHEMICON International, Inc. LIF is protected under US Patent

Analysis Note

Tested negative in both aseptic and microplasmic tests.
The activity of mouse LIF is determined by the ability to induce differentiation of murine M1 myeloid leukemic cells. The minimum detectable concentration of mouse LIF in this assay is 0.5 ng/mL.

Legal Information

CHEMICON is a registered trademark of Merck KGaA, Darmstadt, Germany


Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial

Storage Class Code

12 - Non Combustible Liquids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

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Certificate of Quality

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