Product Specifications for Recombinant Human IGF-I/IGF-1 Protein, CF
E. coli-derived human IGF-I/IGF-1 protein Gly49-Ala118
>97%, by SDS-PAGE under reducing conditions and visualized by silver stain.
<0.10 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
7 kDa, reducing conditions
Measured in a serum-free cell proliferation assay using MCF‑7 human breast cancer cells. Karey, K.P. et al. (1988) Cancer Research 48:4083. The ED50 for this effect is 0.3-1.5 ng/mL.
Scientific Data Examples for Recombinant Human IGF-I/IGF-1 Protein, CF
Bioactivity of Human IGF-1 Protein
Recombinant Human IGF-I / IGF-1 (Catalog # 291-G1) stimulates proliferation in the MCF-7 human breast cancer cell line. The ED50 for this effect is 0.3‑1.5 ng/mL.
Recombinant Human IGF-1 / IGF-1 Protein SDS-PAGE
1 μg/lane of Recombinant Human IGF-I / IGF-1 was resolved with SDS-PAGE under reducing (R) conditions and visualized by silver staining, showing a single band at 7 kDa.
Bioactivity of Human IGF-1 Protein
MALDI-TOF analysis of Recombinant Human IGF-I / IGF-1. The major peak corresponds to the calculated molecular mass, 7650 Da. The minor peak at 7873 is a matrix-associated artifact of the MALDI-TOF.
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or
as an ELISA standard.
In contrast, the carrier free protein is recommended for applications, in which the presence of BSA
Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitute at 200 μg/mL in sterile PBS.
The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
12 months from date of receipt, -20 to -70 °C as supplied.
1 month, 2 to 8 °C under sterile conditions after reconstitution.
3 months, -20 to -70 °C under sterile conditions after reconstitution.
Insulin-like growth factor I (IGF-I or IGF-1), also known as somatomedin C, is the dominant effector of growth hormone and is structurally homologous to proinsulin. Human IGF-1 is synthesized as two precursor isoforms with N- and alternate C‑terminal propeptides (1). These isoforms are differentially expressed by various tissues (1). The 7.6 kDa mature IGF-1 protein is identical between isoforms and is generated by proteolytic removal of the N- and C‑terminal regions. Mature human IGF-1 shares 94% and 96% aa sequence identity with mouse and rat IGF-1, respectively (2), and exhibits cross-species activity. It shares 64% aa sequence identity with mature human IGF-II/IGF-2. Circulating IGF-I is produced by hepatocytes, while local IGF-I is produced by many other tissues in which it has paracrine effects (1). IGF-I induces the proliferation, migration, and differentiation of a wide variety of cell types during development and postnatally (3). IGF-I regulates glucose and fatty acid metabolism, steroid hormone activity, and cartilage and bone metabolism (4‑7). It plays an important role in muscle regeneration and tumor progression (1, 8). IGF-I/IGF-1 binds IGF-I R, IGF-II R, and the insulin receptor, although its effects are mediated primarily by IGF-I R (9). The IGF-I protein associates with IGF binding proteins thereby increasing its plasma half‑life and modulating its interactions with receptors (10).
Philippou, A. et al. (2007) In Vivo 21:45.
Sandberg-Nordqvist, A.C. et al. (1992) Brain Res. Mol. Brain Res. 12:275.
Guvakova, M.A. (2007) Int. J. Biochem. Cell Biol. 39:890.
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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