IGF-1 LR3 is a larger, disulfide-bonded protein rather than a short synthetic peptide, so verifying a lot involves an additional question beyond sequence and purity: whether the molecule folded correctly.
Reversed-phase HPLC and SDS-PAGE
Reversed-phase HPLC separates the target protein from truncated or aggregated species, with the resulting purity figure interpreted per understanding HPLC purity. Because IGF-1 LR3 is produced by recombinant expression rather than solid-phase synthesis, gel-based methods such as SDS-PAGE are also commonly used to confirm approximate molecular weight and detect gross aggregation.
Mass spectrometry for identity
Mass spectrometry confirms the protein's mass matches the expected value for the R3-substituted, N-terminally extended sequence described in its chemistry article — general background on this class of analysis is in HPLC vs. mass spectrometry.
Why correct folding matters more here than for short peptides
A misfolded protein can carry the same mass as the correctly folded form yet behave very differently in a receptor-binding assay, since IGF-1 LR3's internal disulfide bonds govern the three-dimensional structure that its IGF-1 receptor engagement depends on. Mass spectrometry alone cannot distinguish correctly folded from misfolded material with identical covalent composition — functional or binding assays are typically needed alongside analytical confirmation.
Documentation to expect
A lot-specific certificate of analysis with purity, mass, and — where available — activity or binding data — see how to read a CoA.
Product page: IGF-1 LR3 research vials.
Research Use Only. Supplied strictly for laboratory research and development — not for human or veterinary use, consumption, or any therapeutic or diagnostic purpose. This article is research education, not usage guidance.