A practical reference on Peptide content: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-04-02. Anything still debated is marked as such rather than presented as settled.
Regulatory status differs by country, but TB-500 is not an approved pharmaceutical in major jurisdictions. It is commonly sold as a research chemical for laboratory use, which places responsibility for identity and purity on the supplier and the laboratory. Published human data are limited, and most reports involve preclinical models or cell culture. Questions about whether the fragment mimics all actions of thymosin beta-4, and under which conditions, remain open. Independent verification of any material is therefore a practical requirement in research settings.
TB-500 is a synthetic heptapeptide with the sequence Ac-LKKTETQ. It corresponds to a short N-terminal region of thymosin beta-4, a 43-amino-acid protein found in many cell types. The fragment contains an actin-binding motif, which is one reason it appears in laboratory studies of cell migration and cytoskeletal dynamics. TB-500 is not the full-length protein and is produced as a research chemical rather than an approved therapeutic agent. Its molecular weight is approximately 889 Da.
Identity and purity are normally assessed with reversed-phase high-performance liquid chromatography, paired with mass spectrometry to confirm molecular mass. A certificate of analysis reports a purity percentage, usually derived from chromatographic peak area, but that figure does not by itself prove a correct sequence or the absence of counterions. Independent verification may include amino acid analysis or peptide mapping. Batch-to-batch variation is a documented concern in the research chemical market, and the gap between a quoted purity value and actual peptide content can be substantial when the material is a salt or retains residual water.
Lyophilized peptide arrives as a dry cake that should stay sealed until use. Reconstitution is generally performed with sterile water or a buffered solution, and the resulting liquid should be handled gently to limit mechanical stress. Repeated freeze-thaw cycles are widely described as harmful to short peptides, so dividing a reconstituted batch into single-use portions is a common practice. Laboratories also record the solvent, concentration, and date of preparation on the vial label to keep later measurements traceable.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H68N10O14 | Calculated for the acetylated heptapeptide |
| Molecular weight | ~889 Da | Monoisotopic mass approximately 889.0 Da |
| Amino acid sequence | Ac-LKKTETQ | N-terminal acetylated seven-residue peptide |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Water-soluble | Peptides of this size generally dissolve in aqueous media |
Interest in the compound comes largely from studies of the parent protein, which participates in actin sequestration, cell migration and tissue repair processes. Whether a short fragment reproduces those activities is a separate question that remains open in the published record. Many summaries describe mechanisms by analogy to thymosin beta-4 rather than from direct measurements on the fragment. Claims about activity should be treated as provisional unless a cited study specifies the exact peptide, its purity and the assay used.
TB-500 is a laboratory label applied to a short synthetic peptide that is widely described as a fragment of thymosin beta-4, an actin-binding protein present in most mammalian cells. Suppliers and review articles usually present TB-500 as the N-terminal region of that protein, but the exact sequence attached to the name is not consistent across sources. Some product descriptions list a seven-residue chain; others use the label loosely for the parent protein itself. Because of that variation, any technical discussion of TB-500 needs to state which sequence is meant.
Thymosin beta-4 contains 43 amino acids and has a reported molecular mass near 4963 Da. The short fragment most often associated with the TB-500 label, an acetylated chain beginning LKKTETQ, has a reported mass near 889 Da, so the two are easily separated in analytical work. Mass spectrometry and amino acid analysis can confirm which material is present in a given sample. Statements treating TB-500 and thymosin beta-4 as interchangeable are therefore imprecise, even though the two appear together in much of the same literature.
Identity and purity are checked with reversed-phase high-performance liquid chromatography, which separates the target sequence from truncated or deletion analogues, and with mass spectrometry, which confirms the expected molecular mass. Amino acid analysis and peptide mapping give orthogonal confirmation but are used less often outside specialist laboratories. Counter-ion content varies: material purified on trifluoroacetic acid gradients retains trifluoroacetate, and ion exchange can convert the salt form. Residual water and solvent are measured by Karl Fischer titration or thermogravimetric analysis, and any purity figure should be read together with the method used to obtain it.
Lyophilised peptide powders are hygroscopic, and the fragment absorbs atmospheric moisture when a vial is opened at room temperature. Weighing and aliquoting are normally done quickly in a dry environment, and stock solutions are divided into single-use portions before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and can shift the measured content of a vial. These practices are general to synthetic peptides rather than unique to this sequence, but they matter more for short chains kept for long periods.
The seven-residue chain carries several polar and charged side chains, so it dissolves readily in water and in aqueous buffers near neutral pH. No cysteine is present, so disulphide formation is not a concern and reducing agents are unnecessary. Dilute ammonium hydroxide or acetonitrile-water mixtures are sometimes used for stock solutions when initial dissolution is slow. Strongly alkaline conditions and prolonged contact with oxidising agents are avoided because they can modify lysine-containing stretches, and haze in solution usually signals incomplete dissolution or aggregated material.
Purity and identity are separate measurements and are often confused. Reverse-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, reports the share of total peak area belonging to the target compound. Mass spectrometry by electrospray or matrix-assisted laser desorption then checks whether the observed mass matches the expected sequence. Neither measurement alone shows that a vial holds the intended peptide. Peptide content, meaning the fraction of vial mass that is genuine peptide rather than counter-ion, water or residual acid, is reported separately and is frequently lower than the stated purity figure.
The regulatory position is broadly consistent across major jurisdictions: no thymosin beta-4 fragment is an approved medicine, and laboratory material is commonly labelled as not intended for human consumption. Anti-doping rules in sport list thymosin beta-4 and its fragments among prohibited peptide hormones. Because these products travel through research-chemical channels rather than pharmaceutical supply chains, quality varies considerably between vendors. Independent testing of identity, purity and sterility is the only dependable check, and a certificate of analysis describes one batch rather than a supplier's whole catalogue.
Lyophilized peptide powder is normally held desiccated at −20 °C, with −80 °C used for longer storage periods. Allowing a sealed vial to reach room temperature before opening is standard practice, because condensation forming on cold powder introduces moisture. Once dissolved, solutions are typically kept cold and shielded from light. Repeated freeze-thaw cycles are avoided because they encourage aggregation and gradual loss of material. These conventions are general to synthetic peptides rather than unique to any one sequence.
TB-500 is a synthetic seven-amino-acid peptide with the sequence LKKTETQ, corresponding to residues 17 through 23 of the protein thymosin beta-4. The N-terminus is typically acetylated in the described form, giving a monoisotopic mass near 888.5 Da and an average mass of about 889 Da. The designation TB-500 is a catalogue label rather than a formal chemical name, and the same sequence appears in the literature under several alternative abbreviations. It is handled as a research reagent rather than a pharmaceutical product.
Thymosin beta-4 is a 43-residue actin-binding protein found in most mammalian cell types, where it participates in cytoskeletal regulation and cell migration. TB-500 represents only a short fragment of that protein and does not include the remaining residues. Whether the isolated fragment reproduces the full range of activities reported for the intact protein remains an open question. Researchers commonly treat the two as related but distinct entities when comparing results.
=== Harness with buoyancy compensation === The AP Valves Mk4 Jump Jacket is a harness with integral buoyancy jacket specifically designed for commercial diving work with helmets and bells. There is a direct feed to the jacket from the main air supply, via the helmet side-manifold block, from the pneumo line and from bailout, and a system which allows the diver's pneumo to be directly connected to another diver's helmet as an emergency air supply. The harness supports a single or twin cylinder bailout set, allows buoyancy control from slightly negative through neutral, to sightly positive, and has a safety harness for retaining the helmet.The Jump Jacket also serves as a recovery harness for rescues to the bell, and has front and back lifting points.
== Detection in body fluids == Levamisole may be quantified in blood, plasma, or urine as a diagnostic tool in clinical poisoning situations or to aid in the medicolegal investigation of suspicious deaths involving adulterated street drugs. About 3% of an oral dose is eliminated unchanged in the 24-hour urine of humans. A post mortem blood levamisole concentration of 2.2 mg/L was present in a woman who died of a cocaine overdose.
== NFL career == The Washington Redskins signed him on August 15, 2015. This came on the back of Niles Paul and Logan Paulson being placed on the Injured Reserve list. He was waived on August 31, 2015.
1993/931) Friendly Societies Act 1992 (Transitional and Consequential Provisions and Savings) Regulations 1993 (S.I. 1993/932) Finance Act 1991, section 58, (Commencement No. 3) Regulations 1993 (S.I. 1993/933) Legal Aid in Criminal and Care Proceedings (Costs) (Amendment) Regulations 1993 (S.I. 1993/934) Housing Benefit and Community Charge Benefit (Subsidy) (No. 2) Order 1993 (S.I. 1993/935) Certification Officer (Amendment of Fees) Regulations 1993 (S.I. 1993/936) Further Education (Exclusion of Land from Transfer) (No. 2) Order 1993 (S.I. 1993/937) Land Registry Trading Fund Order 1993 (S.I. 1993/938) Land Registration (Determination of Costs) Order 1993 (S.I. 1993/939) Local Government Administration (Matters Subject to Investigation) Order 1993 (S.I. 1993/940) Local Elections (Variation of Limits of Candidates' Election Expenses) (Northern Ireland) Order 1993 (S.I. 1993/941) Copyright (Application to Other Countries) Order 1993 (S.I. 1993/942) Performances (Reciprocal Protection) (Convention Countries) Order 1993 (S.I. 1993/943) European Communities (Definition of Treaties) (International Railway Tariffs Agreements) Order 1993 (S.I. 1993/944) Insurance Companies (Accounts and Statements) (Amendment) Regulations 1993 (S.I. 1993/946) Patents (Supplementary Protection Certificate for Medicinal Products) (Amendment) Rules 1993 (S.I. 1993/947) Chessington Computer Centre Trading Fund Order 1993 (S.I. 1993/948) Income Tax (Interest Relief) (Qualifying Lenders) Order 1993 (S.I. 1993/949) Capital Gains Tax (Gilt-edged Securities) Order 1993 (S.I.
Rudolph Emile 'Rudy' Tanzi is the Joseph P. and Rose F. Kennedy Professor of Neurology at Harvard University, and director of the Genetics and Aging Research Unit and director of the Henry and Allison McCance Center for Brain Health at Massachusetts General Hospital (MGH). Dr. Rudy Tanzi has been investigating the genetics of neurological disease since the 1980s. He co-discovered all three familial early-onset Alzheimer's disease (FAD) genes and several other neurological disease genes including that responsible for Wilson’s disease. His team was the first to use human stem cells to create three-dimensional cell culture organoids of AD, dubbed “Alzheimer's-in-a-Dish”. The 3-D model made drug screening for AD faster and more cost-effective. He has published over 800 research papers and has received the Metropolitan Life Award and Potamkin Prize, the two highest awards for Alzheimer’s research. He is also a member of the National Academy of Medicine and was on the TIME100 Most Influential People in the World list in 2015.
Sources: en.wikipedia.org
Napoleon took the reserve of the Army of the North, and reunited his forces with those of Ney to pursue Wellington's army, after he ordered Marshal Grouchy to take the right wing of the Army of the North and stop the Prussians regrouping. In the first of a series of miscalculations, both Grouchy and Napoleon failed to realise that the Prussian forces were already reorganised and were assembling at the city of Wavre. The French army did nothing to stop a rather leisurely retreat that took place throughout the night and into the early morning by the Prussians. As the 4th, 1st, and 2nd Prussian Corps marched through the town towards Waterloo, the 3rd Prussian Corps took up blocking positions across the river, and although Grouchy engaged and defeated the Prussian rearguard under the command of Lt-Gen von Thielmann in the Battle of Wavre (18–19 June) it was 12 hours too late. In the end, 17,000 Prussians had kept 33,000 badly needed French reinforcements off the field. Napoleon delayed the start of fighting at the Battle of Waterloo on the morning of 18 June for several hours while he waited for the ground to dry after the previous night's rain. By late afternoon, the French army had not succeeded in driving Wellington's forces from the escarpment on which they stood. When the Prussians arrived and attacked the French right flank in ever-increasing numbers, Napoleon's strategy of keeping the coalition armies divided had failed and a combined coalition general advance drove his army from the field in confusion.
=== MeSH D12.644.276 – intercellular signaling peptides and proteins === MeSH D12.644.276.100 – angiogenic proteins MeSH D12.644.276.100.100 – angiopoietins MeSH D12.644.276.100.100.100 – angiopoietin-1 MeSH D12.644.276.100.100.200 – angiopoietin-2 MeSH D12.644.276.100.450 – angiostatic proteins MeSH D12.644.276.100.450.500 – angiostatins MeSH D12.644.276.100.450.750 – endostatins MeSH D12.644.276.100.800 – vascular endothelial growth factors MeSH D12.644.276.100.800.200 – vascular endothelial growth factor a MeSH D12.644.276.100.800.300 – vascular endothelial growth factor b MeSH D12.644.276.100.800.400 – vascular endothelial growth factor c MeSH D12.644.276.100.800.500 – vascular endothelial growth factor d MeSH D12.644.276.100.800.600 – vascular endothelial growth factor, endocrine-gland-derived MeSH D12.644.276.174 – cytokines MeSH D12.644.276.174.050 – autocrine motility factor MeSH D12.644.276.174.200 – chemokines MeSH D12.644.276.174.200.070 – beta-thromboglobulin MeSH D12.644.276.174.200.100 – chemokines, c MeSH D12.644.276.174.200.110 – chemokines, cc MeSH D12.644.276.174.200.120 – chemokines, cxc MeSH D12.644.276.174.200.130 – chemokines, cx3c MeSH D12.644.276.174.200.508 – interleukin-8 MeSH D12.644.276.174.200.600 – macrophage inflammatory proteins MeSH D12.644.276.174.200.600.500 – macrophage inflammatory protein-1 MeSH D12.644.276.174.200.610 – monocyte chemoattractant proteins MeSH D12.644.276.174.200.610.600 – monocyte chemoattractant protein-1 MeSH D12.644.276.174.200.700 – platelet factor 4 MeSH D12.644.276.174.200.750 – rantes MeSH D12.644.276.174.400 – growth substances MeSH D12.644.276.174.400.442 – hematopoietic cell growth factors MeSH D12.644.276.174.400.442.240 – colony-stimulating factors MeSH D12.644.276.174.400.442.240.075 – colony-stimulating factors, recombinant MeSH D12.644.276.174.400.442.240.075.350 – granulocyte colony stimulating factor, recombinant MeSH D12.644.276.174.400.442.240.075.350.275 – filgrastim MeSH D12.644.276.174.400.442.240.075.375 – granulocyte macrophage colony-stimulating factors, recombinant MeSH D12.644.276.174.400.442.240.150 – erythropoietin MeSH D12.644.276.174.400.442.240.150.250 – erythropoietin, recombinant MeSH D12.644.276.174.400.442.240.150.250.250 – epoetin alfa MeSH D12.644.276.174.400.442.240.350 – granulocyte colony-stimulating factor MeSH D12.644.276.174.400.442.240.350.375 – granulocyte colony stimulating factor, recombinant MeSH D12.644.276.174.400.442.240.350.375.275 – filgrastim MeSH D12.644.276.174.400.442.240.375 – granulocyte-macrophage colony-stimulating factor MeSH D12.644.276.174.400.442.240.375.275 – granulocyte macrophage colony-stimulating factors, recombinant MeSH D12.644.276.174.400.442.240.400 – interleukin-3 MeSH D12.644.276.174.400.442.240.500 – macrophage colony-stimulating factor MeSH D12.644.276.174.400.442.240.750 – thrombopoietin MeSH D12.644.276.174.400.442.800 – stem cell factor MeSH D12.644.276.174.400.505 – interleukins MeSH D12.644.276.174.400.505.501 – interleukin-1 MeSH D12.644.276.174.400.505.502 – interleukin-2 MeSH D12.644.276.174.400.505.503 – interleukin-3 MeSH D12.644.276.174.400.505.504 – interleukin-4 MeSH D12.644.276.174.400.505.505 – interleukin-5 MeSH D12.644.276.174.400.505.506 – interleukin-6 MeSH D12.644.276.174.400.505.507 – interleukin-7 MeSH D12.644.276.174.400.505.508 – interleukin-8 MeSH D12.644.276.174.400.505.509 – interleukin-9 MeSH D12.644.276.174.400.505.510 – interleukin-10 MeSH D12.644.276.174.400.505.511 – interleukin-11 MeSH D12.644.276.174.400.505.512 – interleukin-12 MeSH D12.644.276.174.400.505.513 – interleukin-13 MeSH D12.644.276.174.400.505.514 – interleukin-14 MeSH D12.644.276.174.400.505.515 – interleukin-15 MeSH D12.644.276.174.400.505.516 – interleukin-16 MeSH D12.644.276.174.400.505.517 – interleukin-17 MeSH D12.644.276.174.400.505.518 – interleukin-18 MeSH D12.644.276.174.400.800 – transforming growth factor beta MeSH D12.644.276.174.420 – hepatocyte growth factor MeSH D12.644.276.174.440 – interferons MeSH D12.644.276.174.440.890 – interferon type i MeSH D12.644.276.174.440.890.125 – interferon type i, recombinant MeSH D12.644.276.174.440.890.125.100 – interferon alfa-2a MeSH D12.644.276.174.440.890.125.150 – interferon alfa-2b MeSH D12.644.276.174.440.890.125.200 – interferon alfa-2c MeSH D12.644.276.174.440.890.250 – interferon-alpha MeSH D12.644.276.174.440.890.250.100 – interferon alfa-2a MeSH D12.644.276.174.440.890.250.150 – interferon alfa-2b MeSH D12.644.276.174.440.890.250.200 – interferon alfa-2c MeSH D12.644.276.174.440.890.275 – interferon-beta MeSH D12.644.276.174.440.893 – interferon type ii MeSH D12.644.276.174.440.893.510 – interferon-gamma, recombinant MeSH D12.644.276.174.480 – lymphokines MeSH D12.644.276.174.480.350 – interferon type ii MeSH D12.644.276.174.480.372 – interleukin-2 MeSH D12.644.276.174.480.428 – leukocyte migration-inhibitory factors MeSH D12.644.276.174.480.438 – lymphotoxin MeSH D12.644.276.174.480.615 – macrophage-activating factors MeSH D12.644.276.174.480.615.350 – interferon type ii MeSH D12.644.276.174.480.625 – macrophage migration-inhibitory factors MeSH D12.644.276.174.480.640 – neuroleukin MeSH D12.644.276.174.480.700 – suppressor factors, immunologic MeSH D12.644.276.174.480.750 – transfer factor MeSH D12.644.276.174.500 – monokines MeSH D12.644.276.174.500.400 – interleukin-1 MeSH D12.644.276.174.500.800 – tumor necrosis factor-alpha MeSH D12.644.276.174.750 – tumor necrosis factors MeSH D12.644.276.174.750.500 – lymphotoxin MeSH D12.644.276.174.750.750 – tumor necrosis factor-alpha MeSH D12.644.276.211 – endothelial growth factors MeSH D12.644.276.249 – endothelins MeSH D12.644.276.249.225 – endothelin-1 MeSH D12.644.276.249.235 – endothelin-2 MeSH D12.644.276.249.245 – endothelin-3 MeSH D12.644.276.500 – ephrins MeSH D12.644.276.500.100 – ephrin-A1 MeSH D12.644.276.500.200 – ephrin-A2 MeSH D12.644.276.500.300 – ephrin-A3 MeSH D12.644.276.500.400 – ephrin-A4 MeSH D12.644.276.500.500 – ephrin-A5 MeSH D12.644.276.500.600 – ephrin-b1 MeSH D12.644.276.500.700 – ephrin-b2 MeSH D12.644.276.500.800 – ephrin-b3 MeSH D12.644.276.625 – epidermal growth factor MeSH D12.644.276.750 – fibroblast growth factors MeSH D12.644.276.750.110 – fibroblast growth factor 1 MeSH D12.644.276.750.120 – fibroblast growth factor 2 MeSH D12.644.276.750.130 – fibroblast growth factor 3 MeSH D12.644.276.750.140 – fibroblast growth factor 4 MeSH D12.644.276.750.150 – fibroblast growth factor 5 MeSH D12.644.276.750.160 – fibroblast growth factor 6 MeSH D12.644.276.750.170 – fibroblast growth factor 7 MeSH D12.644.276.750.180 – fibroblast growth factor 8 MeSH D12.644.276.750.190 – fibroblast growth factor 9 MeSH D12.644.276.750.200 – fibroblast growth factor 10 MeSH D12.644.276.812 – i-kappa b kinase MeSH D12.644.276.875 – kinins MeSH D12.644.276.875.169 – bradykinin MeSH D12.644.276.875.169.400 – kallidin MeSH D12.644.276.875.654 – kininogens MeSH D12.644.276.875.654.350 – kininogen, high-molecular-weight MeSH D12.644.276.875.654.400 – kininogen, low-molecular-weight MeSH D12.644.276.875.900 – tachykinins MeSH D12.644.276.875.900.354 – eledoisin MeSH D12.644.276.875.900.475 – kassinin MeSH D12.644.276.875.900.500 – neurokinin a MeSH D12.644.276.875.900.550 – neurokinin b MeSH D12.644.276.875.900.800 – physalaemin MeSH D12.644.276.875.900.866 – substance p MeSH D12.644.276.937 – neuregulins MeSH D12.644.276.937.750 – neuregulin-1 MeSH D12.644.276.952 – parathyroid hormone-related protein MeSH D12.644.276.968 – platelet-derived growth factor MeSH D12.644.276.968.650 – proto-oncogene proteins c-sis MeSH D12.644.276.976 – somatomedins MeSH D12.644.276.976.400 – insulin-like growth factor i MeSH D12.644.276.976.420 – insulin-like growth factor ii MeSH D12.644.276.984 – transforming growth factors MeSH D12.644.276.984.700 – transforming growth factor alpha MeSH D12.644.276.984.720 – transforming growth factor beta MeSH D12.644.276.992 – tumor necrosis factors MeSH D12.644.276.992.500 – lymphotoxin MeSH D12.644.276.992.750 – tumor necrosis factor-alpha MeSH D12.644.276.996 – wnt proteins MeSH D12.644.276.996.500 – wnt1 protein MeSH D12.644.276.996.750 – wnt2 protein
Drug Information Association (DIA) EVENT: DIA/FDA Orphan Drug Designation Workshop November 2010 Archived 2010-10-28 at the Wayback Machine European Commission - The Orphan drugs strategy List of European Orphan Drugs USA Food and Drug Administration: The Orphan Drug Act (as amended) US FDA List of Orphan Designations and Approvals
== Development and social impact == John Rolfe of Virginia used this species of tobacco to break the Spanish monopoly on tobacco in 1612. He did so by obtaining Nicotiana tabacum - the coveted plant he had designs to replace Nicotiana rustica with. Up until 1612, Nicotiana rustica was Virginia's only tobacco crop, and was found by Englishmen to be too bitter for enjoyment. Rolfe, by successfully planting, maintaining, and curing Nicotiana tabacum until sale (by removing all superfluous leaves and applying as little water as possible during curing), made Virginia a potential competitor with Spain's colonies. This transitioned the colony to a cash-crop focused one, monocropping tobacco by 1613, the year the first shipment (of 4 barrels) arrived in London. By 1617, the quality of Virginia tobacco had made it the gold standard in European markets, which have become insatiable- 20,000lbs of tobacco was exported there that year. These exports grew exponentially, doubling to 40,000lbs the following year (the year the first enslaved Africans arrive in America), and reaching 60,000lbs by 1620. The money obtained from tobacco exports was used, in turn, to fund the purchasing of more European indentured servants and especially enslaved Africans to fulfill the rising labor demand. In the 17th century, 75% of all colonists in Virginia had come as servants, indentured (with a term of 4 to 7 years of service) or Africans in perpetuity (for life), the latter being preferred as they were cheaper sources of labor:
{\displaystyle {\begin{aligned}&{\frac {\beta }{\gamma }}\leq 1\Rightarrow \lim _{t\to +\infty }I(t)=0,\\[6pt]&{\frac {\beta }{\gamma }}>1\Rightarrow \lim _{t\to +\infty }I(t)=\left(1-{\frac {\gamma }{\beta }}\right)N.\end{aligned}}}
Sources: en.wikipedia.org
TB-500 is a synthetic heptapeptide corresponding to a fragment of thymosin beta-4. It is used in laboratory research and is not an approved drug.
No. Thymosin beta-4 is a 43-amino-acid protein, while TB-500 represents only a short N-terminal segment. The two should not be treated as interchangeable in experimental design.
It is often called a thymosin beta-4 fragment, Tβ4 fragment, or Ac-LKKTETQ. The name TB-500 is mainly a commercial or catalog label rather than a formal chemical name.
Dry lyophilized powder is usually kept frozen, desiccated, and out of direct light. Sealed vials are not opened until needed, because moisture uptake can degrade short peptides. Longer archival storage is often done at lower temperatures than routine working stock.