Research compound overview
Epitalon research peptide: tetrapeptide chemistry, telomerase assays and quality standards
Epitalon (also written epithalon) is a synthetic tetrapeptide studied in cell culture and biochemical research. This guide covers its structure, the laboratory systems where it appears in the literature, and the analytical documentation to expect with any research-grade lot.
Epitalon at a glance
These are the identifying details researchers usually confirm before planning an experiment. They describe the chemical material only.
| Compound | Epitalon (Epithalon, AEDG peptide) |
|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly (four amino acids) |
| Molecular formula | C14H22N4O9 |
| Molecular weight | about 390.35 g/mol |
| CAS number | 307297-39-8 |
| Physical form | Lyophilized white to off-white solid |
| Typical documentation | HPLC purity, mass spectrometry identity, lot number, third-party testing |
| Intended use | Qualified laboratory research only |
What is Epitalon?
Epitalon is a short synthetic peptide made of four amino acids: alanine, glutamic acid, aspartic acid and glycine. It was designed in the 1980s and 1990s by Russian researchers who were studying epithalamin, a polypeptide extract of the pineal gland. The aim was to identify a small, defined sequence that could be produced reproducibly by chemical synthesis instead of tissue extraction.
Because it is a defined four-residue sequence, Epitalon is easy to characterize and straightforward to compare between lots. That makes it a convenient reference peptide for telomerase and cellular senescence assays, where reproducibility of the reagent is as important as the assay itself.
From pineal extract to a defined synthetic sequence
Early work on pineal gland extracts described a mixture of peptides, and mixtures are hard to standardize. The shift to a single synthetic tetrapeptide solved that problem. A defined sequence can be made by solid-phase peptide synthesis, purified by preparative HPLC and verified by mass spectrometry, so every lot can be checked against the same specification.
For the bench scientist, the practical consequence is that results can be traced to a known molecule. When a paper reports an effect in cultured cells, the reagent should be identifiable by sequence, mass and lot, and the control peptide should be equally well defined. This guide uses that standard throughout.
Areas of laboratory research
The published literature on Epitalon touches several experimental areas. The groupings below describe model systems, not any use beyond the laboratory.
Telomerase and telomere assays
Cultured cell lines are used to examine telomerase reverse transcriptase expression, telomerase activity and telomere length under defined culture conditions.
Replicative senescence models
Serially passaged fibroblast cultures provide a controlled system for examining population doublings, senescence markers and growth arrest.
Gene expression analysis
Transcript-level studies in cultured cells compare expression panels between treated and control arms, usually by quantitative PCR or RNA sequencing.
How telomerase and telomere endpoints are measured
Telomere biology experiments depend on choosing an endpoint that matches the question. The methods below are the ones most often seen in the literature.
- TRAP assay. The telomeric repeat amplification protocol measures telomerase activity in a cell extract by extending a primer and amplifying the products.
- RT-qPCR for hTERT. Quantitative PCR reports transcript levels of the catalytic subunit and is a common first-pass readout.
- qPCR telomere length. The telomere to single-copy gene ratio is a high-throughput estimate of relative telomere length.
- Terminal restriction fragment analysis. Southern blotting of digested genomic DNA gives an absolute length distribution.
- Q-FISH. Fluorescence in situ hybridization quantifies telomere signal at the single-chromosome level.
No single method is sufficient on its own. Reviewers increasingly expect two orthogonal readouts, such as an activity assay together with a length measurement.
Designing a clean in vitro experiment
Telomere and senescence experiments run for weeks, so small inconsistencies compound. These design points matter most.
- Use a defined control peptide. A scrambled sequence with the same composition shows whether an effect depends on sequence order.
- Match passage number. Treated and control cultures should have the same population doubling level at the start.
- Hold the medium constant. Serum lot, supplements and plating density change growth kinetics and must not drift between arms.
- Test for mycoplasma. Contamination alters telomerase and growth readouts and is easy to miss.
- Record the lot. Keep the reagent lot number with every dataset so a result can be repeated with the same or a second lot.
- Replicate independently. Independent biological replicates on separate days carry more weight than many wells from a single run.
Analytical standards for a short, polar tetrapeptide
Short acidic peptides such as Epitalon behave differently from larger peptides on a reversed-phase column. They are polar, elute early and can overlap with solvent-front artifacts, so the chromatogram deserves a careful read.
- HPLC purity. Check the main peak, the integration baseline and the gradient, not only the headline percentage.
- Mass spectrometry. Electrospray ionization should show the protonated molecular ion near m/z 391 for the intact tetrapeptide.
- Peptide content. Net peptide content, often by amino acid analysis, tells you how much of the powder is peptide rather than counter-ion and moisture.
- Lot tracking. The lot on the label must match the lot on the report.
Browse the certificates that are available in the Certificate of Analysis library.
How to read a certificate of analysis for a short peptide
A useful report lets you verify the material yourself. Three checks cover most of what matters.
1. Identity
The observed mass in the spectrum should match the expected mass of the intact tetrapeptide, with no unexplained dominant ions.
2. Purity
Look at the chromatogram. One dominant peak and a flat baseline are what you want; many small peaks near the main one are a warning.
3. Traceability
The compound name, lot number and test date on the report must match the vial you received.
Our quality standards explain how each lot is documented before release.
Selected published literature
These PubMed records describe in vitro and biochemical work related to Epitalon and telomerase biology. They are provided for scientific context only.
Glossary: telomere and senescence terms
Clear terminology prevents most misunderstandings when reading telomere literature or comparing a certificate of analysis between vendors. These are the terms used on this page.
| Telomere | The repetitive DNA sequence and protein complex that caps the end of a linear chromosome and shortens with successive cell divisions in most somatic cell cultures. |
|---|---|
| Telomerase | A ribonucleoprotein enzyme that adds telomeric repeats to chromosome ends. Its catalytic subunit is encoded by hTERT. |
| Population doubling | A count of how many times a culture has doubled, used instead of simple passage number to compare cultures at equivalent replicative age. |
| Replicative senescence | A stable growth arrest reached after extended culture, usually accompanied by markers such as senescence-associated beta-galactosidase and elevated p16 or p21. |
| TRAP assay | Telomeric repeat amplification protocol, a PCR-based method that reports telomerase activity in a cell extract. |
| Scrambled control | A peptide with the same amino acids as the test peptide in a different order, used to test sequence specificity. |
| Net peptide content | The percentage of a lyophilized powder that is peptide, as opposed to counter-ion, bound water and residual salts. |
| Counter-ion | The ion, commonly trifluoroacetate or acetate, that accompanies a peptide after purification and contributes to the powder mass. |
Epitalon in the context of short-peptide research
Epitalon belongs to a group of very short peptides, from two to four residues long, that were derived from tissue extracts and studied mainly by research groups in Russia. Much of that literature has been published in regional journals and, in many cases, has not been independently replicated in Western laboratories.
That context is useful for a bench scientist. It means that a careful, well-controlled replication using a fully characterized reagent has real scientific value. It also means that claims should be read critically: check which cell type, which endpoint and which controls were used, and whether the effect was shown with more than one assay.
A documented Epitalon lot, a scrambled control and two independent telomere readouts make a stronger experiment than any single positive result. That is the standard this guide is written to support.
Epitalon research FAQ
What is Epitalon?
Epitalon is a synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. In the laboratory it is used as a defined reference peptide in cell culture, telomerase and senescence research models.
Is Epitalon sold for human or animal use?
No. Synagenics supplies Epitalon strictly as a research-use-only material for qualified laboratory work. It is not a drug, supplement or cosmetic, and nothing on this page is a claim about use in people or animals.
How is the purity of research-grade Epitalon verified?
Purity is reported by reversed-phase HPLC as a percentage of the main peak, and identity is confirmed by mass spectrometry.
Where can I see a Certificate of Analysis?
Certificates for tested lots are published in the public Certificate of Analysis library at synagenics.com/coas/.
Which assays are used in telomerase research?
Common endpoints include the TRAP assay for telomerase activity, RT-qPCR for hTERT expression, qPCR or terminal restriction fragment analysis for telomere length, and Q-FISH for single-chromosome resolution.
Why use a scrambled control peptide?
A scrambled peptide with the same amino acid composition shows whether an observed effect depends on the specific sequence rather than on general peptide properties in the medium.
Related research
Continue exploring the Synagenics research library.
Looking for research-grade Epitalon?
Browse the open certificate of analysis library to see how we document tested lots.
For qualified laboratory research use only. Not for human or animal use. These statements have not been evaluated by the US Food and Drug Administration.