What is Thymalin?
Our molecular dataset assigns no CAS number, formula, molecular weight, sequence or residue count to Thymalin, only the classification as a thymus peptide bioregulator complex. That is not a gap in the record, it is the nature of the material. Thymalin belongs to the cytomedine category, the organ-extract stage of the Khavinson programme, in which peptide fractions were isolated from animal tissue and characterized as mixtures. This distinguishes it from thymosin alpha-1, a single chemically defined sequence.
The programme behind this class was led by Vladimir Khavinson at the St Petersburg Institute of Bioregulation and Gerontology. Cytomedines were later distilled into cytogens, short synthetic peptides such as Vilon and Vesugen, on the hypothesis that a few residues carry the activity of the whole fraction and act by binding promoter-region DNA or histones to modulate transcription.
That hypothesis is unproven, and it applies only loosely to an undefined mixture in any case. Published thymic peptide research covers T-cell maturation markers and immune signaling in animal and cell models, but the composition of any given complex preparation depends on source tissue and extraction method, which is precisely why lot-to-lot analytical profiling matters more here than for a synthetic peptide.
Reconstitution & handling
The material dissolves in bacteriostatic or sterile water introduced slowly down the vial wall. Concentration is the labeled milligram content divided by the diluent volume, expressed as total peptide mass per millilitre rather than molarity, since a mixture has no single molecular weight. Swirl gently rather than shaking, because the larger components are more prone to surface denaturation than short synthetic peptides.
Storage & stability
Sealed vials are kept at -20 degrees Celsius, protected from light and moisture, with the cake dry and intact. Reconstituted material is refrigerated at 2 to 8 degrees Celsius, aliquoted for single use, and shielded from repeated freeze-thaw cycles, which affect a heterogeneous mixture unevenly because larger components aggregate first. Drift in the chromatographic profile is a more informative stability signal than clarity or color.
How it's tested
Analysis is by reverse-phase HPLC at 214 and 220 nanometres, reported as a chromatographic fingerprint against a reference profile rather than a main-peak purity figure, which has no meaning for a mixture. Mass spectrometry characterizes the principal components and confirms the expected mass distribution. Total peptide content is quantified so the labeled figure reflects peptide rather than salts and water.