Selank specifications and molecular characteristics
The technical specification for Selank, the Selank research material supplied by Selank Labs: molecular formula C33H57N11O9, average molecular weight 751.87 g/mol, 7 residues, supplied as a white lyophilized powder. Each item is explained below.
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Specification table
| Product | Selank |
|---|---|
| Type | Synthetic heptapeptide |
| Molecular formula | C33H57N11O9 |
| Molecular weight | 751.87 g/mol (average) |
| Length | 7 residues |
| Sequence | TKPRPGP |
| N-terminus | Free amine (Thr1) |
| C-terminus | Free acid (Pro7) |
| CAS number | 129954-34-3 |
| Form | White lyophilized powder |
| Vial sizes | 10 mg |
| Purity specification | ≥95% (HPLC-UV) |
| Purity, current lots | 99.77% |
| Identity specification | Confirmed by LC-MS |
| Testing laboratory | Freedom Diagnostics (independent) |
| Storage | Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening. |
| Designation | Research use only |
Current lot results against specification
Every current lot meets the release specification. Current lots test at 99.77% by HPLC-UV against a specification of ≥95%, and identity is confirmed by LC-MS on every lot.
Selank molecular formula
The molecular formula of Selank is C33H57N11O9.
Selank molecular weight
The average molecular weight of Selank is 751.87 g/mol. "Average" means it is calculated from natural isotope abundances, which is the value used to predict the ions seen in LC-MS. With this weight, Selank is expected at m/z 752.9 with one charge and m/z 376.9 with two charges.
Selank sequence
TKPRPGP
Positions 1–4 (TKPR) are the tuftsin sequence; positions 5–7 (PGP) are the stabilizing extension.
Structure and modifications
Selank is linear, with a free N-terminal amine and a free C-terminal carboxylic acid. It has no cysteine, methionine or tryptophan, so it carries none of the residues most prone to oxidation. Lysine 2 and arginine 4 are the only charged side chains.
Physical form
White lyophilized powder, recorded as the appearance on every certificate. Lyophilization (freeze-drying) removes water, which slows most chemical degradation. What lyophilized means.
Purity and identity specifications
Selank Labs’ stated release specification is ≥95% HPLC-UV purity with identity confirmed by LC-MS. The current lot, KB55627, reported 99.77%. How purity is measured, or how specifications fit into the quality and supply-chain process.
Analytical and testing methods
HPLC-UV for purity, LC-MS for identity and laboratory quantitation for net content, performed on every lot by Freedom Diagnostics. LAL endotoxin testing (USP <85>) and PCR microbial screening are reported for lots where they were run. Testing and quality control.
Research designation
Selank is designated research use only: supplied for laboratory research by qualified personnel. Research use only policy.
Buy Selank
10 mg vials. Current lot KB55627 tested at 99.77% purity with identity confirmed by LC-MS. Current purchasing is available through Klow.bio.