The IGFs are mitogenic polypeptide growth factors that stimulate the proliferation and survival of various cell types including muscle, bone, and cartilage tissue in vitro. IGFs are predominantly produced by the liver, although a variety of tissues produce the IGFs at distinctive times. The IGFs belong to the Insulin gene family, which also contains insulin and relaxin. The IGFs are similar by structure and function to insulin, but have a much higher growth-promoting activity than insulin. IGF-II expression is influenced by placenta lactogen, while IGF-I expression is regulated by growth hormone. Both IGF-I and IGF-II signal through the tyrosine kinase type I receptor (IGF-IR), but, IGF-II can also signal through the IGF-II/Mannose-6-phosphate receptor. Mature IGFs are generated by proteolytic processing of inactive precursor proteins, which contain N-terminal and C-terminal propeptide regions.
>97% by SDS-PAGE and analyzed by silver stain.
<0.1 EU/µg as determined by the LAL method
The biological activity of Human IGF-I was determined in a serum-free cell proliferation assay using the human cell line MCF-7 (Karey, K.P. et al., Cancer Research, 1988, 48:4083). The expected ED50 for this effect is typically 0.3 - 1.5 ng/ml.
Protein Accession No.
Amino Acid Sequence
gpetlcgael vdalqfvcgd rgfyfnkptg ygsssrrapq tgivdeccfr scdlrrlemy caplkpaksa
N-terminal Sequence Analysis
State of Matter
Predicted Molecular Mass
The predicted molecular weight of Recombinant Human IGF-I is Mr 7.5 kDa. However, the actual molecular weight as observed by migration on SDS-PAGE is 7 kDa (reducing conditions).
This recombinant protein was 0.2 µm filtered and lyophilized from modified Dulbecco’s phosphate buffered saline (1X PBS) pH 7.2 – 7.3 with no calcium, magnesium, or preservatives present.
Storage and Stability
This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.
Country of Origin
Next Day Ambient
NCBI Gene Bank
IMPORTANT Use lot specific datasheet for all technical information pertaining to this recombinant protein.
Products are for research use only. Not for use in diagnostic or therapeutic procedures.