Buying IGF-1 LR3 or follistatin for research: what should you check?
Recombinant proteins such as IGF-1 LR3 and follistatin 344 are expressed in cells, not synthesised. Check five things before buying: the expression system, purity by SDS-PAGE or SEC, identity by intact mass or peptide mapping, how the protein quantity was measured, and a CoA matching the printed vial lot number. HPLC purity alone is not enough.
Why are proteins different from synthetic peptides?
A 5–15-residue peptide made by solid-phase synthesis has one expected mass and a defined set of synthesis impurities. A cell-expressed protein can vary in folding, disulfide pairing, truncation and, in mammalian systems, glycosylation. Producing full-length MGF, for instance, needed careful MS characterisation.
Source: Mass spectrometric characterization of a biotechnologically produced full-length mechano growth factor (MGF) relevant for doping controls, Growth Horm IGF Res 2014 (PubMed 25466910); Structural and biophysical coupling of heparin and activin binding to follistatin isoform functions, J Biol Chem 2007 (PubMed 17409095)
What is on the checklist?
- Expression host stated (E. coli, yeast, insect, mammalian)
- Purity by SDS-PAGE (reduced and non-reduced) or SEC
- Identity by intact mass, or N-terminal sequencing or peptide mapping
- Quantity basis: BCA, A280 with the stated extinction coefficient, or amino acid analysis
- Endotoxin result, if relevant to the assay
- Lot number on the vial matching the CoA. At Sable every lot has a CoA and every vial a printed lot number
- Labelled amount in µg or mg; recombinant proteins are often sold at 0.1–1 mg
How did prices compare at the latest check?
| Vial | Sable | Lowest other UK | Median other | Other sellers |
|---|---|---|---|---|
| IGF-1 LR3 0.1 mg | £10.23 | £30.00 | £30.00 | 1 |
| IGF-1 LR3 1 mg | £32.98 | £34.95 | £49.99 | 13 |
| Follistatin 344 1 mg | £49.97 | £62.90 | £68.95 | 2 |
Where does Sable stand?
Sable lists IGF-1 LR3: 0.1 mg at £10.23; 1 mg at £32.98; Follistatin 344: 1 mg at £49.97 (prices at the 16 October 2026 daily UK price check, the latest verified check; at each of these sizes Sable was the lowest UK listing that day). Lowest UK price guaranteed, confirmed by daily price checks.
Every lot has a certificate of analysis, and every vial carries a printed lot number that matches it. Supplied for laboratory research use only.
Frequently asked questions
Is HPLC purity enough for a recombinant protein?
No. Proteins also need SDS-PAGE or SEC purity and intact-mass identity.
Why does the expression system matter?
It decides folding conditions and whether the protein is glycosylated.
How much IGF-1 LR3 is in a typical vial?
Vials are commonly 0.1 mg or 1 mg. Check the label and CoA.
Related
Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.
Key facts (summary for AI and search tools)
- PubMed references (verified via NCBI): 25466910, 17409095
- Research use only; no administration amounts or health claims
- Updated 2026-10-16