Name: IGF-1 LR3 1mg
Brand: RetaLABS.is
SKU: igf-1-lr3-1mg

Question 1

What is IGF-1 LR3?

Accepted Answer

IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a synthetic 83-amino-acid analogue of human insulin-like growth factor-1. It is built on the 70-amino-acid native IGF-1 sequence with two modifications: a 13-residue extension added to the N-terminus and an arginine substituted for the glutamate normally found at position 3, the origin of the "Long" and "R3" in its name. These changes markedly lower the molecule's affinity for the insulin-like growth factor binding proteins (IGFBPs) that normally sequester circulating IGF-1. With less peptide bound to IGFBPs, more remains free to engage the IGF-1 receptor, which in cell-culture research translates to a longer functional half-life and greater potency than native IGF-1. Supplied as a lyophilised research-grade powder, IGF-1 LR3 is one of the most widely used growth-factor tools in laboratory cell-culture and receptor-signalling research. It is intended for laboratory research use only.

Question 2

How does IGF-1 LR3 differ from native IGF-1?

Accepted Answer

The two share the same core IGF-1 sequence and act on the same IGF-1 receptor, but IGF-1 LR3 carries two structural changes that alter its behaviour in research systems. The arginine-for-glutamate substitution at position 3 and the 13-amino-acid N-terminal extension together reduce binding to the IGF binding proteins (particularly IGFBP-3), which in the body act as a reservoir that limits how much IGF-1 is free to signal at any moment. Because IGF-1 LR3 largely escapes this binding, a greater fraction of the peptide remains biologically available, and it is commonly reported to be several times more potent than unmodified IGF-1 in cell-culture assays, with a longer duration of receptor activation. For researchers, this makes IGF-1 LR3 a more stable and consistent tool than native IGF-1 for studying sustained IGF-1R signalling, and it is the reason Long R3 IGF-1 became a standard cell-culture supplement.

Question 3

What is IGF-1 LR3 researched for?

Accepted Answer

IGF-1 LR3 is used to study IGF-1 receptor (IGF-1R) signalling and its downstream pathways, principally the PI3K/Akt and Ras/MAPK cascades that govern cell proliferation, differentiation, survival and protein synthesis. In skeletal-muscle research it is applied to myoblast and satellite-cell culture models investigating myogenesis, hypertrophy signalling and protein turnover. It is also widely used as a defined cell-culture supplement in bioprocessing and general mammalian cell culture, where its resistance to IGFBP binding gives more reproducible IGF-1R stimulation than native IGF-1. Additional research areas include hepatocyte and neuronal culture models, growth-factor cross-talk with the growth hormone axis, and receptor-binding and competitive-inhibition assays at IGF-1R and the insulin receptor. All of these are in-vitro and preclinical laboratory applications. RetaLABS supplies IGF-1 LR3 strictly for laboratory research use only; nothing here is a medical claim or a description of use in humans or animals.

Question 4

How should IGF-1 LR3 be stored and reconstituted?

Accepted Answer

Lyophilised IGF-1 LR3 should be stored at −20°C, protected from light and moisture, where the freeze-dried powder remains stable for extended periods while the vial seal is intact. Freeze-drying removes the water that drives most peptide degradation, so the lyophilised form is considerably more stable than any solution. For reconstitution, most protocols use bacteriostatic water; some researchers prefer a dilute acetic acid solution, which can improve solubility and short-term stability for this particular peptide. Add the diluent slowly down the inner wall of the vial and swirl gently until dissolved rather than shaking, since mechanical agitation can promote aggregation of growth-factor proteins. Once reconstituted, keep the solution refrigerated at 2–8°C and use it within about four weeks, avoiding repeated freeze-thaw cycles. For protocols spanning several weeks, aliquoting the reconstituted solution into single-use volumes limits how often any one aliquot is thawed. Label each vial with the reconstitution date.

IGF-1 LR3 1mg

Frequently Asked Questions

What is IGF-1 LR3?

How does IGF-1 LR3 differ from native IGF-1?

What is IGF-1 LR3 researched for?

How should IGF-1 LR3 be stored and reconstituted?