MOTS-c certificate of analysis: how to read a COA
What a certificate of analysis is
A certificate of analysis (COA) is a lot-specific document in which a supplier records the results of analytical testing on one batch of material. For a MOTS-c research vial such as the MOTS C 10MG listing referenced by this site, a COA typically reports identity confirmation, purity by high-performance liquid chromatography (HPLC), and mass spectrometry data. It is a snapshot of one lot at one point in time, prepared under the supplier’s stated methods.
Identity versus purity
Identity testing answers the question of whether the material is the intended compound. For MOTS-c, that means confirming the 16-amino-acid sequence described by Lee and colleagues in 2015, usually by comparing mass spectrometry results against the calculated molecular weight of the published sequence. Purity testing answers a different question: what fraction of the material is the intended compound. HPLC purity is reported as the main peak area relative to all detected peaks, and by itself it says nothing about what the remaining fraction contains.
What a COA cannot establish
- A COA does not establish biological activity. Purity by HPLC does not show that a peptide retains the behavior observed in any published study.
- A COA does not establish sterility, endotoxin levels, or solubility unless those tests are explicitly reported with methods and acceptance criteria.
- A COA does not establish safety or efficacy for any application. Research peptides are not approved for human or veterinary use.
- Supplier-issued documents are not independent verification. Where third-party confirmation is claimed, the document should name the testing laboratory and the methods applied.
Regulatory labeling context
In the United States, research-use-only labeling for in vitro diagnostic products is described in federal regulation at 21 CFR Part 809. Material labeled for laboratory investigation is distinct from approved medicines, and the labeling does not imply regulatory review of the material for any other purpose. The site research-use-only policy explains how that status applies to every listing referenced here.
Practical review checklist
- Match the lot number on the vial to the lot number printed on the COA.
- Confirm that identity (mass spectrometry) and purity (HPLC) are both reported with named methods, not only a pass statement.
- Check the report date and ask whether retesting is scheduled for older lots.
- Retain the document with laboratory records so experimental results can be traced to the exact material used.
References
- Lee C, Zeng J, Drew BG, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015. PubMed 25738459
- Lee C, Kim KH, Cohen P. MOTS-c: a novel mitochondrial-derived peptide regulating muscle and fat metabolism. Free Radic Biol Med. 2016;100:182-187. PubMed 27235108
For research use only. Not for human or veterinary use. No therapeutic claims are made. Research findings do not establish safety or efficacy for human or veterinary use.
Related research: MOTS-c research evidence and limitations