In brief: Selank is a synthetic heptapeptide derived from the endogenous tetrapeptide tuftsin and stabilised by the sequence Pro-Gly-Pro. In research it is used as a model compound for regulatory peptides in the nervous system. Anyone sourcing Selank for laboratory purposes can choose between a lyophilised vial (5 or 10 mg) and a ready-dissolved solution (20 mg / 10 ml, 2 mg/ml). In both cases what matters is a batch-specific certificate of analysis with an HPLC chromatogram and mass spectrometry – and storage that suits the format.
What is Selank?
Selank (sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro) was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is based on tuftsin, a naturally occurring fragment of immunoglobulin G, extended by three amino acids (Pro-Gly-Pro) to increase enzymatic stability. In the scientific literature, Selank is studied mainly in three contexts:
- modulation of GABAergic signalling pathways and its role in animal models of stress-associated behaviour
- influence on the expression of neurotrophic factors (including BDNF) in the hippocampus
- interaction between the immune and nervous systems as a tuftsin analogue
Selank has been registered as a medicinal product in Russia since 2009; there is no approval in the EU. For labs in the EU it is therefore purely a research compound. The scientific background with literature references is summarised on the Selank page in the peptide library.
Vial or ready-made solution – which format for which purpose?
Two formats are available on the market. They do not differ in the active compound, but in handling, shelf life and documentation.
| Lyophilised vial | Ready-made solution (2 mg/ml) | |
|---|---|---|
| Form | Dry substance, reconstituted in the lab | Ready-to-use solution (laboratory series) |
| Nominal amounts at Peptélia | 5 mg / 10 mg | 20 mg in 10 ml |
| Advantage | Free choice of solvent and concentration; longest shelf life | Defined concentration (2 mg/ml), no reconstitution needed |
| Disadvantage | Reconstitution is a point of failure (foaming, wrong volume) | Limited shelf life as a solution; concentration cannot be changed |
| Typical use | Experimental series with variable concentration, reference material | Laboratory series at a fixed concentration |
For series in which the concentration is varied, the vial is the more flexible choice. If you need a fixed concentration across many experiments, the ready-made formulation saves the reconstitution step – and with it one source of error. The peptide calculator shows how to work out reconstitution volumes.
How to recognise a reputable supplier
Selank is a small peptide that is cheap to synthesise – the supply is correspondingly large, and the quality correspondingly variable. Four checkpoints:
- Batch-specific COA. Lot number on the certificate = lot number on the vial. An HPLC chromatogram with a purity figure and a mass-spectrometric confirmation of identity (target mass around 751 Da) belong with it. What else a COA has to contain is set out in the COA guide.
- Lab analysis per batch. One COA per batch, available to view, is the standard. Peptélia tests in its own lab by HPLC and UV/Vis and publishes the COA for each batch.
- Net peptide content. With small peptides carrying basic residues (lysine, arginine) in particular, the share of counterions in the lyophilisate is appreciable. 99 % HPLC purity is not 99 % peptide – what counts for the concentration calculation is the net content.
- Transparent labelling. “Research Use Only” is not a formality but the intended purpose of the goods. Suppliers that advertise with promises of application should be treated critically (not legal advice; observe national regulations) – details in our research use disclaimer.
Storage and shelf life
Lyophilised Selank is stable for years at −20 °C, dry and protected from light; short periods at 4 °C are not critical. After reconstitution with bacteriostatic water, the solution should be refrigerated and used up within a few weeks – the limiting factor here is less the peptide chemistry than the sterility limit of the solvent. The ready-made solution is stored refrigerated and not frozen. In detail: storing peptides correctly.
Selank at Peptélia
Peptélia stocks Selank as a lyophilised vial in 5 mg (€29.90) and 10 mg (€39.90) and as a ready-made solution 20 mg / 10 ml (€82.00). Every batch is tested in our own lab by HPLC and UV/Vis spectroscopy, and the COA can be viewed before purchase. Dispatch on the next business day from the EU, free shipping from €100, and bacteriostatic water is included with every vial order. All formats at a glance: buy Selank.
Related: Semax, the second Russian neuropeptide in the range, is derived not from tuftsin but from an ACTH fragment – the comparison is worth making if the two compounds are to be set against each other in one model.
Note: For research use only (Research Use Only) – not for use in humans or animals.
