01 / Naming
One name, two very different molecules.
In the cited analytical study, TB-500 is Ac-LKKTETQ: a seven-residue fragment with an acetylated N-terminus (Ho et al. 2012). Those seven residues are positions 17–23 of mature thymosin beta-4, a 43-residue chain (UniProt P62328).
Pioneer’s TB-500 is the 43-amino-acid form, the same length as thymosin beta-4. A record that says only TB-500 could mean either molecule, so check its chain length before comparing results.
| In the cited study | Pioneer’s TB-500 | |
|---|---|---|
| Chain length | 7 residues | 43 amino acids |
| Relation to thymosin beta-4 | Positions 17–23 (LKKTETQ), acetylated at the N-terminus | The same length as the 43-residue chain |
Not thymosin alpha-1.
Thymosin alpha-1 is a different peptide: 28 residues with a sequence of its own, not a form of thymosin beta-4 or TB-500. Read the Thymosin Alpha-1 guide
02 / Molecular architecture
A closer look at the chain.
Pioneer’s TB-500 is a single chain of 43 amino acids, the same length as full-length thymosin beta-4. Length is one part of its identity; the full sequence, the chemistry at each end and the salt form belong to the lot’s own record.
- 43 amino acids
- Thymosin-related research
- Chromatographic analysis
- Mass spectrometry
Reference information: [1][2]. Actual lot identity must be verified separately.
Two numberings for the same residues.
UniProt numbers thymosin beta-4 from its precursor, which begins with a methionine that the mature chain does not keep. The LKKTETQ residues are therefore positions 18–24 in that numbering and 17–23 in the mature numbering the cited study uses. Check which numbering a record follows before comparing positions.
Two analytical views of a peptide.
Liquid chromatography separates sample components under a defined method. Mass spectrometry examines ion mass-to-charge information. The cited analytical work combines these approaches. Retention behavior and mass information answer complementary questions; neither should be relabeled as a universal description of every material sold under the same short name.
03 / Where it also appears
TB-500 in blends.
Three blends each hold 10mg of TB-500, and in all three it is the 43-amino-acid form.
- BPC-157 + TB-500With 10mg BPC-157, in a 20mg vial.
- GLOWWith 50mg GHK-Cu and 10mg BPC-157, in a 70mg vial.
- KLOWWith 50mg GHK-Cu, 10mg BPC-157 and 10mg KPV, in an 80mg vial.
- BPC-157 vs TB-500A reference page: the two chains side by side, by length and public record.
04 / Read the evidence
Research & analytical context.
The cited study used liquid chromatography and mass spectrometry to characterize a short synthetic fragment from an active region of thymosin beta-4, which it called TB-500; it did not examine the 43-amino-acid form supplied here. Its methods show how peptide analytes are told apart, while its retention times and masses belong to that fragment.
The distinction that matters
A research paper describes its tested material. Match your lot’s certificate for the full sequence and other product-specific details of the 43-amino-acid form.
05 / From reference to record
Know the lot, too.
A publication describes its own test material. Your lot’s certificate describes what was tested on that lot. Keep the compound name, batch number and reported methods together when reviewing a result.
Identity & composition
Check sequence or chemical form, terminal modifications, counterion and—where relevant—each blend component.
Analytical results
Read purity, content, sterility and endotoxin results as separate measurements. Only call a test passed when the actual report supports it.
Handling & storage notes
Lyophilized material: Store at −20°C; protect from light and moisture.
Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.
How to store lyophilized peptides06 / Reference questions
A few details, explained.
Is TB-500 the same as thymosin beta-4?
The name alone does not settle it. Thymosin beta-4 is a 43-residue chain, and the cited analytical study used TB-500 for a seven-residue fragment of it, positions 17–23. The TB-500 supplied here is the 43-amino-acid form, the same length as thymosin beta-4; your lot’s certificate is the record for its full sequence.
Can a paper’s test material define every TB-500 listing?
No. A paper characterizes the material it actually examined. A shared name does not establish that another sample has the same full identity or analytical profile; your lot’s certificate is the record for the material in your vial.
07 / Continue reading
Go to the source.
Each source is labeled by its type. External sources are not Pioneer batch certificates.