Peptide Reference Desk
MGF vs PEG-MGF: PEGylation changes more than the product name
MGF and PEG-MGF should not share one molecular-weight field or evidence summary. PEGylation changes identity, heterogeneity and analytical requirements.
The prefix is part of the molecule
MGF is used for an IGF-1 splice-variant-related peptide concept. PEG-MGF describes material presented as PEGylated. Adding polyethylene glycol changes expected mass, chromatographic behavior, heterogeneity and exposure; it is not a storage upgrade applied after identity testing.
A PEG-MGF COA needs extra answers
| Field | Required detail |
|---|---|
| Peptide construct | Full sequence and terminal form |
| PEG reagent | Nominal size, architecture and attachment chemistry |
| Conjugation | Site, occupancy and unconjugated peptide |
| Distribution | How PEG-related heterogeneity was assessed |
Evidence follows the tested construct
A result for unmodified MGF cannot be copied into a PEG-MGF record. Before citing a paper, check whether the conjugate was structurally characterized and whether the assay compared matched molar concentrations.
Verify with primary records
Use the primary paper, current regulator label or lot-linked analytical file for the claim it supports. A search result is a route to evidence, not the evidence itself.