膜杰作
Star Staining
产品描述（Product Details）
Laminin 521 (LN521) is a recombinant human protein that provides a defined surface for in vitro feeder-free culture of multiple human pluripotent stem cells (PSCs). LN521 has been proven to maintain normal growth characteristics and stemness in multiple PSC lines without simultaneous differentiation, which includes ESC, iPSC, MSC etc. In addition, LN521 has been demonstrated to support PSC growth for >10 passages without any signs of karyotypic abnormalities and to maintain the ability of PSCs to differentiate into all three germ line lineages.
Flexible & Compatible
Laminin 521 could work well in any commercial stem cell media. Meanwhile, it could support the attachment and expansion of hPSCs both in single cells or small colonies.
Stemness maintenance
Laminin 521 is the biologically relevant hPSCs extracellular matrix. It is crucial for the growth and stemness maintenance of hPSCs in human through its binding to cell receptors a6β1 integrin.
Enhance cell differentiation
Due to the diverse biorelevant environment, laminin 521 could also enhance cell differentiation, polarization and organization of target cell types, including neuron, hepatocytes, cardiomyocytes, retinal pigmented epithelial cells, pancreatic β-cells and so on.
Reduce Variability
LN521 is a defined, recombinant human protein with better lot-to-lot consistency that reduces variability in your PSC cultures.
产品参数（Key parameter）
| Purity (SDS PAGE) | > 95% |
| Mycoplasma Test | Negative |
| Sterility Test | Negative |
| Integrin Binding Assay | 0.5 nM ＜ KD ＜ 5 nM |
| Endotoxin Test | < 0.01 EU per μg |
| Host Cell Protein | < 0.5 ng/µg |
| Host Cell DNA | < 0.02 ng/μg |
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.
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.
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 12 months under sterile conditions after reconstitution;
- 2-8°C for 3 months under sterile conditions after reconstitution.
活性（Bioactivity）-Stem Cell CultureView Protocol
Laminin 521 (LA5-H5261) could maintain the stemness of iPSC at least Passage 5. Immunofluorescent staining indicated that the iPSCs expressed high levels of pluripotency associated markers Sox2, TRA-1-60, SSEA4 and OCT4.
Laminin 521 (LA5-H5261) could maintain the stemness of iPSC at least Passage 5. FACS data indicated that the iPSCs expressed high levels of pluripotency associated markers OCT4 and SOX2.
Normal karyotype (46, XX) was found in hiPSCs with Laminin 521 (LA5-H5261) coating after 10 passages.
活性（Bioactivity）-BLI
Loaded Human ITGA6&ITGB1 Heterodimer Protein, His Tag&Tag Free (Cat. No. IT1-H52W7) on HIS1K Biosensor, can bind Human Laminin 521 Protein, premium grade (Cat. No. LA5-H5261) with an affinity constant between 0.50 nM - 5.00 nM as determined in BLI assay (ForteBio Octet Red96e) (QC tested).
Protocol
稳定性（Stability）
The BLI based assay shows batch-to-batch consistency between Acro's GMP and PG Laminin 521.
