By BioLabs Research · Last reviewed: October 8, 2026
G1-S, G2-T and G3-R are three catalog codes on this storefront. They are not three grades or strengths of one reagent, and this page does not rank them against each other. Each code is its own catalog record, with its own carton label, its own lot numbers and its own certificate of analysis (COA). This note explains how a receiving lab should keep those records apart, and which quality markers belong on the paperwork for any lyophilized research peptide.
All three are listed for laboratory research use only (RUO). They are not for human or veterinary use, and this page gives no preparation, administration or dosing guidance.
Why the catalog uses codes
Purchasing and receiving teams work from paperwork, not from shorthand. A short catalog code that stays the same on the product page, the carton, the invoice and the lot certificate makes it harder to swap records by mistake. The code is an inventory key. It tells the receiving lab which lot file to open. It is not a description of what the material does.
Current listing status
| Code | Catalog URL | Status on this storefront (checked 1 Oct 2026) |
|---|---|---|
| G1-S | /products/g1-s | Active listing, lyophilized vial |
| G2-T | /products/g2-t | Not an active listing right now. The URL sends visitors back to the catalog. |
| G3-R | /products/g3-r | Active listing, lyophilized vial |
If your paperwork names G2-T, contact the desk before you order. We will confirm what is available instead of guessing.
One code, one lot file
Receiving goes wrong when two codes share a file. When a vial arrives, check four things:
- Carton code matches the order. The code on the carton and the code on the invoice should be the same catalog code.
- Lot number matches the certificate. The lot number printed on the vial or carton should appear on the COA. A "house COA" without a lot number does not document that vial.
- Test date and method are stated. A purity figure without a method ID, column and detection wavelength is an orphan number.
- Identity is shown, not asserted. The COA should report an observed molecular mass from mass spectrometry next to the expected value for that catalog code.
If any of these is missing, mark the lot "identity unresolved" in your inventory system and ask for a revised certificate. Do not move it into active stock first.
Quality markers worth asking about
The same documentation standard applies to every synthetic peptide on this catalog. The peer-reviewed analytical literature describes several markers:
- HPLC area percent. This is the share of UV-absorbing signal in the main peak under one stated method. It is not the same as net peptide content, because it does not see water, counter-ions or residual solvent. See HPLC area percent vs net peptide content.
- Mass spectrometry identity. The observed mass should match the expected mass for the catalog record. Unexplained peaks can point to deletion sequences, truncations or modified residues. Reviews of peptide impurities list these as common synthesis by-products (D'Hondt et al., 2014).
- Impurity profile. Studies of commercial synthetic peptides have found impurities that changed downstream assay results (Currier et al., 2008). One report used NMR to find an undeclared constituent in custom peptides (Choules et al., 2020). So a single purity number is not enough to describe a lot.
- Counter-ion statement. Peptides purified by reversed-phase HPLC often carry trifluoroacetate (TFA). Residual TFA has been reported to affect some cell-based assays (Cornish et al., 1999). A COA that states the counter-ion helps labs plan their controls.
- Endotoxin. If a lot is meant for cell-culture work, ask whether an endotoxin result is on file for that lot.
Handling and storage as laboratory material
Lyophilized peptides are usually shipped and stored as a dry cake or powder. General practice in the stability literature applies to all three codes (Manning et al., 2010):
- Store sealed vials cold, dry and away from light, as the lot paper states. Freezer storage at −20 °C is common for lyophilized peptides.
- Limit how often a vial warms up and cools down. Repeated temperature cycling and moisture exposure are known causes of degradation pathways such as oxidation, deamidation and aggregation.
- Log the date received, the storage location and the lot number. Keep the COA in the same record.
- Follow your institution's chemical-hygiene and waste procedures for research reagents.
The storefront does not publish preparation instructions. Your lab's own validated SOP decides how material is handled at the bench.
Keep the paper trail clean
A clean inventory trail looks like this:
- one catalog code per inventory record;
- one lot number per certificate;
- one certificate filed against each received vial;
- any change of supplier or lot noted as a new record, never merged into the old one.
This matters most for sites that hold more than one coded listing. Codes that look alike (G1-S and G3-R, for example) are easy to transpose on handwritten labels. Printed labels and barcode scanning reduce that risk.
What this page does not do
This page does not compare biological activity, suggest which code suits a protocol, or describe any use outside the laboratory. It gives no dosing guidance. Questions about which catalog code your protocol names should go to the desk before you order.
Next step: Contact the desk to request the lot certificate for the code you need, or read Lot docs are not a purity percentage.
References
- D'Hondt M, Bracke N, Taevernier L, et al. Related impurities in peptide medicines. J Pharm Biomed Anal. 2014;101:2–30. https://pubmed.ncbi.nlm.nih.gov/25044089/
- Currier JR, Galley LM, Wenschuh H, et al. Peptide impurities in commercial synthetic peptides and their implications for vaccine trial assessment. Clin Vaccine Immunol. 2008;15(2):267–276. https://pubmed.ncbi.nlm.nih.gov/18077621/
- Choules MP, et al. NMR reveals an undeclared constituent in custom synthetic peptides. J Pharm Biomed Anal. 2020;178:112915. https://pubmed.ncbi.nlm.nih.gov/31671336/
- Cornish J, Callon KE, Lin CQ, et al. Trifluoroacetate, a contaminant in purified proteins, inhibits proliferation of osteoblasts and chondrocytes. Am J Physiol. 1999;277(5):E779–E783. https://pubmed.ncbi.nlm.nih.gov/10567002/
- Manning MC, Chou DK, Murphy BM, et al. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. https://pubmed.ncbi.nlm.nih.gov/20143256/
Research use only. Not for human or veterinary use, self-administration or therapeutic use. No dosing guidance. Laboratory reagent listing only.