膜杰作
Star Staining
分子别名（Synonym）
LIF,CDF,DIA,HILDA,MLPLI
表达区间及表达系统（Source）
Human LIF Protein, premium grade (LIF-H5215) is expressed from human 293 cells (HEK293). It contains AA Ser 23 - Phe 202 (Accession # P15018-1).
Predicted N-terminus: Ser 23
It is produced under our rigorous quality control system that incorporates a comprehensive set of tests including sterility and endotoxin tests. Product performance is carefully validated and tested for compatibility for cell culture use or any other applications in the early preclinical stage. When ready to transition into later clinical phases, we also offer a custom GMP protein service that tailors to your needs. We will work with you to customize and develop a GMP-grade product in accordance with your requests that also meets the requirements for raw and ancillary materials use in cell manufacturing of cell-based therapies.
Request for sequence
蛋白结构（Molecular Characterization）
This protein carries no "tag".
The protein has a calculated MW of 19.7 kDa. The protein migrates as 37 kDa±3 kDa under reducing (R) condition, and 39 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under non-reducing (NR) condition (SDS-PAGE) due to glycosylation.
内毒素（Endotoxin）
Less than 0.01 EU per μg by the LAL method.
宿主蛋白残留（Host Cell Protein）
<0.5 ng/µg of protein tested by ELISA.
宿主核酸残留（Host Cell DNA）
<0.02 ng/μg of protein tested by qPCR.
无菌（Sterility）
Negative
支原体（Mycoplasma）
Negative.
纯度（Purity）
>95% as determined by SDS-PAGE.
>90% as determined by SEC-MALS.
制剂（Formulation）
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4 with trehalose as protectant.
Contact us for customized product form or formulation.
重构方法（Reconstitution）
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.
存储（Storage）
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
- -20°C to -70°C for 24 months in lyophilized state;
- -70°C for 3 months under sterile conditions after reconstitution.
电泳（SDS-PAGE）
Human LIF Protein, premium grade on SDS-PAGE under reducing (R) and non-reducing (NR) conditions. The gel was stained with Coomassie Blue. The purity of the protein is greater than 95% (With Star Ribbon Pre-stained Protein Marker).
SEC-MALS
The purity of Human LIF Protein, premium grade (Cat. No. LIF-H5215) is more than 90% and the molecular weight of this protein is around 30-40 kDa verified by SEC-MALS.
Report
活性（Bioactivity）-Bioactivity CELL BASE
Human LIF Protein, premium grade (Cat. No. LIF-H5215) stimulates proliferation of TF-1 cells. The specific activity of Human LIF Protein, premium grade is > 1.40 X 10^6 U/mg (QC tested).
Protocol
活性（Bioactivity）-ELISA
Immobilized Human LIF Protein, premium grade (Cat. No. LIF-H5215) at 1 μg/mL (100 μL/well) can bind Human LIF R, Fc Tag (Cat. No. LIR-H4252) with a linear range of 0.004-0.125 μg/mL (QC tested).
Protocol
背景（Background）
Leukemia inhibitory factor, or LIF, an interleukin 6 class cytokine, is a protein in cells that affects cell growth and development.Leukemia Inhibitory Factor has several functions such as cholinergic neuron differentiation, control of stem cell pluripotency, bone & fat metabolism, mitogenesis of factor dependent cell lines & promotion of megakaryocyte production in vivo.
Removal of LIF pushes stem cells toward differentiation, but they retain their proliferative potential or pluripotency. Therefore LIF is used in mouse embryonic stem cell culture. It is necessary to maintain the stem cells in an undifferentiated state, however genetic manipulation of embryonic stem cells allows for LIF independent growth, notably overexpression of the gene Nanog. LIF is not required for culture of human embryonic stem cells.
