IGF-1 LR3 (Long R3 IGF-I) is a recombinant analogue of human insulin-like growth factor-I. It has an arginine substituted for glutamic acid at position 3 and a 13-amino-acid N-terminal extension. Contexx Research supplies IGF-1 LR3 in Canada as a 1 mg lyophilized protein for cell-culture and receptor research.
IGF-1 LR3 specifications
| Compound | IGF-1 LR3 (Long R3 IGF-I) |
|---|---|
| Vial size | 1 mg |
| Form | Lyophilized powder |
| Purity | See lot COA |
| Description | Human IGF-I with Arg3 substitution and 13-residue N-terminal extension (83 residues) |
| Storage (unopened) | −20 °C, dry, protected from light |
Research overview
Both modifications reduce binding to IGF-binding proteins while keeping activity at the type 1 IGF receptor, so IGF-1 LR3 stays biologically available for longer in serum-containing systems. It was developed in Adelaide, Australia, alongside des(1-3)IGF-I, and is widely used as a cell-culture supplement in bioprocessing.
Rodent studies by Tomas and colleagues compared IGF-I with variants that bind IGFBPs poorly, in rats given dexamethasone, and found the variants more potent on nitrogen-balance measures [1]. In vitro, a study in L6 myogenic cells examined how recombinant IGFBP-3 affects IGF-I- and LR3-IGF-I-stimulated proliferation and differentiation [2].
Analytical laboratories also study IGF-1 LR3. Kohler and colleagues identified a His-tagged Long-R3-IGF-I in an unregulated product, a case that shows why identity testing by mass spectrometry matters [3].
Selected references
- Tomas FM et al. Biochem J. 1992. PubMed 1371669
- Xi G et al. J Cell Physiol. 2004. PubMed 15254966
- Kohler M et al. Growth Horm IGF Res. 2010. PubMed 20675162
Storage and handling
IGF-1 LR3 ships as a lyophilized (freeze-dried) powder. Dry material is far more stable than material in solution, so keep it in its dry, sealed state until you need it.
- Store unopened vials of IGF-1 LR3 at −20 °C, dry and protected from light. Let the vial reach room temperature before opening to limit condensation.
- Prepare stock solutions in a solvent suited to your assay, label them with concentration and date, and keep them at 2–8 °C for short-term use.
- For longer storage of solutions, divide them into single-use aliquots and freeze them; avoid repeated freeze–thaw cycles.
- Handle with gloves and eye protection, following your laboratory’s standard chemical-hygiene practice.
See our guide to storing lyophilized peptides in the lab for more detail.
Quality and testing
Contexx Research independently tests every batch it releases. A lot-specific COA for IGF-1 LR3 isn’t linked on this page yet. For questions about testing, contact info@contexxresearch.ca.
We don’t list purity figures in this description; the lot COA is the reference for identity and purity. Researchers should confirm identity and concentration with their own analytical methods where their protocol requires it.
Frequently asked questions
What’s included when I order IGF-1 LR3 1 mg?
One sealed vial containing 1 mg of IGF-1 LR3 as a lyophilized powder. Reconstitution solution is sold separately.
Does IGF-1 LR3 come with a Certificate of Analysis (COA)?
Every batch Contexx Research releases is independently tested. A lot-specific COA isn’t linked on this page yet; for testing questions, contact info@contexxresearch.ca.
How fast is shipping in Canada?
Orders are processed Monday to Friday, and most orders ship within 24 hours from Mississauga, Ontario, in secure, tamper-evident packaging. Orders placed on Friday afternoon (after the 12:00 PM ET cut-off) ship on Monday, when Canada Post resumes pickup, or on the next business day if Monday is a statutory holiday. Once your order ships, delivery typically takes 1–3 business days in Ontario and Quebec and 2–6 business days in the rest of Canada, and a tracking number is emailed to you. Orders over $250 CAD shipped within Canada qualify for free standard shipping. See our Shipping Policy for details.
How should IGF-1 LR3 be stored?
Store unopened vials at −20 °C, dry and protected from light. After reconstitution, keep solutions at 2–8 °C for short-term use, or freeze single-use aliquots and avoid repeated freeze–thaw cycles.
What does “research use only” mean?
“Research use only” means IGF-1 LR3 is sold only as a reference material for in-vitro laboratory and analytical research by qualified professionals. It is not for use in humans or animals, not for diagnostic use, and not a drug, natural health product, food, supplement or cosmetic.
Research use only
IGF-1 LR3 is sold by Contexx Research Inc. strictly as a reference material for in-vitro laboratory research and analytical use by qualified professionals. It is not a drug, natural health product, food, dietary supplement or cosmetic. It is not intended for use in humans or animals, for diagnostic purposes, or for ingestion or any other form of administration to a living organism. Nothing on this page describes or implies any effect in humans or animals. Purchasers are responsible for handling, storage and disposal in line with applicable laws and their institution’s policies. By ordering, you confirm that you are purchasing for legitimate laboratory research and agree to our Terms and Conditions.
Reviews
There are no reviews yet.