Thymosin Alpha-1

Thymosin Alpha-1 is one of the older immunology peptides in continuous research circulation. Allan Goldstein’s group at NIH pulled the first thymosin fractions out of calf thymus tissue in the early 1970s, and by 1977 they had narrowed the activity down to a single 28-amino-acid acetylated peptide. That peptide is what sits in this vial. It is also what later went on to become thymalfasin, the INN given to SciClone’s clinical preparation Zadaxin, currently approved in roughly thirty countries for chronic hepatitis B and used as an adjuvant alongside interferon and chemotherapy. The product you are buying here is the synthetic research-grade equivalent of that molecule, not the licensed pharmaceutical.

The molecule, in plain terms

Thymosin Alpha-1 is not an independent protein. It is a fragment, residues 1 to 28, cleaved from a much longer precursor called prothymosin alpha (PTMA). What makes it pharmacologically interesting is the acetyl group sitting on the N-terminal serine, which is required for the peptide’s reported immune activity in published in vitro work. Strip the acetyl and the activity drops. Worth checking against any CoA you receive from any supplier, including ours.

Note for anyone cross-referencing this against Thymosin Beta-4 or TB-500: despite the shared name, the alpha and beta thymosins come from entirely different gene families. Beta thymosins are actin-sequestering peptides. Alpha-1 is an immune modulator. The naming is historical, dating back to when crude thymic fractions were lettered before anyone knew what was actually in them.

Lot release criteria

• Identity: acetyl-PTMA(1-28), confirmed by mass spectrometry against theoretical mass 3108.27 Da
• Purity: >98% by reversed-phase HPLC, every batch
• Form: lyophilised white powder, acetate salt, sealed under inert gas
• Vial: 5mg, single-use crimp-sealed glass
• Origin: manufactured in UK and EU facilities under documented chain of custody
• Paperwork: batch-matched HPLC and MS CoA in the shipping box; refund if the spec on the page is not matched by the spec in the report

Where it tends to show up in the literature

If you are working in TLR9-driven dendritic cell activation, plasmacytoid DC interferon-alpha output, CD4/CD8 ratio recovery models, or any of the hepatitis-B and hepatitis-C clinical-adjuvant follow-on assays, the Thymosin Alpha-1 publication trail goes back forty years and is unusually well-mapped for an immunology peptide. The earlier Goldstein and Naylor work covered T-cell maturation in nude-mouse models. The more recent SciClone-adjacent clinical literature spans sepsis, ARDS, and oncology adjuvant settings. Whatever lineage your protocol is built on, the relevant references almost certainly cite the acetylated PTMA(1-28) form. That is what we ship.

Bulk and turnaround

Around 90% of UK orders are delivered inside 48 hours. Stock sits in a UK warehouse, so customs and rerouting through the EU do not enter the picture. For ten vials or more, particularly if you need lot-matching across a multi-arm study, message the team through live chat during UK office hours and we will quote per-lot. The people on chat are humans inside UK working hours, not an offshore queue and not a bot. They can also pull a CoA for any current lot before you order if your ethics paperwork wants it up front.

One thing worth knowing about reconstitution

Thymosin Alpha-1 is reasonably soluble in sterile or bacteriostatic water at the working concentrations most assays use. It is more stable at acidic pH than neutral, so if you are seeing peculiar activity drop-off after a few freeze-thaw cycles, check the pH of your buffer before you blame the peptide. Solid at minus twenty, working aliquots at four degrees for short windows only, and avoid repeated freezing.

Sold strictly for in vitro laboratory research. Not for human or veterinary use. UK 18+.