By BioLabs Research · Last reviewed: October 28, 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 keeps those records apart, and which quality markers belong on the paperwork for any lyophilized research peptide.
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, and it carries no information about strength or grade.
Current listing status
| Code | Catalog page | Status on this storefront (checked 8 Oct 2026) |
|---|---|---|
| G1-S | G1-S catalog listing | Active listing, lyophilized vial |
| G2-T | — | Not an active listing right now. The old address sends visitors back to the catalog. |
| G3-R | G3-R catalog listing | 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 in 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, which reviews of peptide impurities list as common synthesis by-products (D'Hondt et al., 2014).
- Impurity profile. A study of commercial synthetic peptides found impurities that changed downstream assay results (Currier et al., 2008). A single purity number is therefore 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.
Reading the certificate for a coded listing
A coded listing puts more weight on the certificate, because the code itself says nothing about the material. Read the COA from the top down: header first (catalog code, lot number, test date), then the identity result, then purity, then the notes on counter-ion and water. Our guide on how to read lot documents walks through each field in that order, and the hosted certificates in our COA library show what a complete lot record looks like.
Two checks catch most filing errors. First, the code printed on the COA header must be the code on the carton, character for character. Second, the expected mass on the COA must be the value for that code's catalog record, not a value copied from another listing. If either check fails, the certificate belongs to a different record.
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, and keep the COA in the same record.
- Follow your institution's chemical-hygiene and waste procedures for research reagents.
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 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. When a lab retires a code from its own inventory, the lot files should stay archived under that code rather than being folded into another record, so the history of each vial can still be traced.
Next step: Contact the desk to request the lot certificate for the code you need.
Related reading
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/
- 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/
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