---
title: "Buying IGF-1 LR3 or follistatin for research: what should you check? | Sable Peptides"
description: "Recombinant proteins such as IGF-1 LR3 and follistatin 344 need different checks from synthetic peptides: expression system, SDS-PAGE purity, intact mass, quantity basis and activity data. A buyer checklist. Research use only."
canonical: https://www.sablepeptides.co.uk/guides/buyer-checklist-for-recombinant-protein-research-materials
dateModified: 2026-10-16
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# 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)](https://pubmed.ncbi.nlm.nih.gov/25466910/); [Structural and biophysical coupling of heparin and activin binding to follistatin isoform functions, J Biol Chem 2007 (PubMed 17409095)](https://pubmed.ncbi.nlm.nih.gov/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

-   [IGF-1 LR3 vs MGF](/guides/igf-1-lr3-vs-mgf-vs-peg-mgf)
-   [Follistatin 344](/guides/follistatin-344-recombinant-glycoprotein-explained)
-   [Growth factor prices](/guides/uk-growth-factor-and-protein-research-material-prices-october-2026)
-   [Cheapest IGF-1 LR3 UK](/cheapest-igf-1-lr3-uk)

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