The short version of reconstitution fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-07 and is reviewed periodically as new material appears.
Thymosin beta-4 was isolated from calf thymus in the early 1980s and later characterised as an abundant intracellular actin-sequestering protein. Interest in short synthetic fragments grew once the actin-binding motif had been mapped to the middle of the sequence. TB-500 came out of that line of work as a truncated analogue rather than a natural isolate, and it is now sold mainly to laboratories. Published studies on the fragment have been largely in vitro or in animal models, and controlled human trials remain sparse, so claims about effects in people rest on extrapolation.
Literature and online discussion often conflate TB-500 with full-length thymosin beta-4, even though the two differ in size and are not interchangeable in analytical terms. The fragment is produced by solid-phase peptide synthesis, and the product is a defined seven-residue chain rather than a biological extract. Because the term is a trade-style label, two vendors may supply materials of the same nominal sequence but different counter-ion content, purity, or water content. Comparisons across studies are therefore difficult unless the exact sequence and purity are reported.
Detection in biological samples relies on mass spectrometry, typically liquid chromatography coupled to tandem mass spectrometry after peptide extraction and enrichment. Intact peptides can also be confirmed by high-resolution mass measurement together with fragmentation data. Detection windows in urine are short because the peptide is degraded by proteases and cleared quickly, and concentrations are low. Many jurisdictions treat the compound as a prohibited substance in sport, grouped with peptide hormones and related factors, while it is not an approved therapeutic product. Identity and purity statements therefore rest on certificates of analysis, ideally issued by an independent laboratory.
Material is normally supplied as a lyophilised powder in a sealed vial. The powder is hygroscopic, so exposure to humid air leads to water uptake, caking and gradual loss of the fluffy texture that indicates a good freeze-dry. Vials are best kept sealed with desiccant, protected from light and stored cold. Letting a cold vial warm to room temperature before opening reduces condensation on the contents. Purity is normally reported from a chromatographic run, and that figure applies to the batch as tested rather than to the vial after repeated opening.
Once dissolved, the peptide is far less stable than the dry powder. Aqueous solutions are subject to hydrolysis, oxidation at susceptible residues and gradual loss of material through adsorption onto glass and plastic surfaces. Terminal glutamine can cyclise under some conditions, producing a related species that complicates purity assessment. Dilute solutions tend to lose a larger fraction of material to surfaces than concentrated ones. Buffers, pH and ionic strength all influence the rate of change, so stability figures are only meaningful when those parameters are stated alongside the storage interval.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Supplied as a lyophilised cake in sealed vials |
| Solubility class | Freely soluble in water | Polar and charged side chains dominate the sequence |
| Typical storage temperature | -20 °C or below | Dry and dark; a desiccant is often recommended |
| Identity confirmation | Mass spectrometry | Observed mass compared with the theoretical value |
| Common synonyms | Thymosin beta-4 fragment | Also written as T beta 4 fragment 17-23 |
Controlled human trials of the short fragment are scarce. Much of what appears in review articles is extrapolated from animal models or from studies of the parent protein, and literature searches return a larger body of cardiac and ophthalmic work on thymosin beta-4 than on the abbreviated peptide. Regulatory treatment differs by jurisdiction, and in several countries the material is handled as a research chemical rather than an approved therapeutic. Statements about human benefit should be read as provisional.
Biological interest in this peptide centers on its relationship to actin dynamics. Thymosin beta-4 binds monomeric actin through an LKKTET motif, and a short sequence carrying that motif can compete with other actin-binding proteins in cell-free preparations. Investigators propose that such competition shifts the balance between filament assembly and disassembly, which in turn affects how readily a cell extends protrusions and migrates. Most of the supporting observations come from cultured cells and purified protein systems rather than from intact organisms.
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.
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.
Grade 1: Only some of the fibers in the ligament are torn, and the injured site is moderately painful and swollen. Function in the joint will be unaffected for the most part. Grade 2: Many of the ligament fibers are torn, and pain and swelling is moderate. The functionality of the joint is compromised. Grade 3: The soft tissue is completely torn, and functionality and strength on the joint is completely compromised. In most cases, surgery is needed to repair the damage.
== Structure == Draculin is a single-chain protein composed of 708 amino acids, weighing about 83 kDa with a pI of 4.1-4.2. When reduced, the gel electrophoresis data indicates a slightly higher molecular mass suggesting intra-chain disulphide bonds. There are two different structural forms of Draculin. However, the two forms do not significantly differ from the other. Both structures are able to and do bind to coagulation factors IXa and Xa. The main difference is evident in inhibition activity. One structural form will inhibit factor IXa and the other Xa. The inhibitory activity of one factor is not affected by the presence of the other. FXa-Draculin complex is a two-step mechanism that, through experimental conditions, is irreversible.
=== Transit === On December 16, 2025, Pritzker signed into law the Illinois People Over Parking Act, which disburses $1.5 billion to address post-COVID-19 budget shortfalls for Chicagoland-area transit authorities to avoid service cuts; reduces the farebox revenue share of total funding from 50% to 25%, since post-pandemic reductions in ridership made these expectations unreasonable; and disburses $169 million to downstate transit agencies to cover similar budget shortfalls. It prevents transit agencies from transferring funding for operations to capital investment. Local jurisdictions are prohibited from establishing minimum parking requirements within half a mile of transit rail stations and bus hubs or one-eighth mile of corridors with combined bus route frequency of 15 minutes or less during peak periods under this legislation. The bill also reorganizes the Regional Transportation Authority into the Northern Illinois Transit Authority, which is intended to centralize decision-making power away from individual counties and synchronize operations of the Chicago Transit Authority, Metra, and Pace. The NITA board is to have 20 members, five assigned by the mayor of Chicago, the Cook County President, and the governor, and five by the five collar counties, where 15 votes are needed to affirm board actions, or 12 if two affirmative votes from each of the four appointing authorities are cast; and a majority of CTA, Metra, and Pace board members are to be simultaneously staffed by NITA board members.
World War I St. Mihiel Meuse-Argonne Lorraine 1918 World War II Sicily Naples-Foggia Normandy (with arrowhead) Rhineland (with arrowhead) Ardennes-Alsace Central Europe Armed Forces Expeditions Dominican Republic Grenada Panama Southwest Asia Defense of Saudi Arabia Liberation and Defense of Kuwait
The concept of yin and yang is also applicable to the human body; for example, the upper part of the body and the back are assigned to yang, while the lower part of the body is believed to have the yin character. Yin and yang characterization also extends to the various body functions, and – more importantly – to disease symptoms (e.g., cold and heat sensations are assumed to be yin and yang symptoms, respectively). Thus, yin and yang of the body are seen as phenomena whose lack (or over-abundance) comes with characteristic symptom combinations:
Sources: en.wikipedia.org
== External links == David Hawgood, One-Place Genealogy, Hawgood, 2001 ^ Society for One-Place Studies - worldwide society for individuals and groups interested in studying one-place family and/or local history
The term bioorthogonal chemistry refers to any chemical reaction that can occur inside of living systems without interfering with native biochemical processes. The term was coined by Carolyn R. Bertozzi in 2003. Since its introduction, the concept of the bioorthogonal reaction has enabled the study of biomolecules such as glycans, proteins, and lipids in real time in living systems without cellular toxicity. A number of chemical ligation strategies have been developed that fulfill the requirements of bioorthogonality, including the 1,3-dipolar cycloaddition between azides and cyclooctynes (also termed copper-free click chemistry), between nitrones and cyclooctynes, oxime/hydrazone formation from aldehydes and ketones, the tetrazine ligation, the isocyanide-based click reaction, and most recently, the quadricyclane ligation.
== Interpretation == A reference range is usually defined as the set of values 95 percent of the normal population falls within (that is, 95% prediction interval). It is determined by collecting data from vast numbers of laboratory tests.
=== Use as forage === In former times, Jerusalem artichoke was used as forage for domesticated cattle, horses, and pigs. The plant has valuable nutrient contents and various bioactive compounds, and so is used today as an animal feed source or for the health of several animal species. Pigs, for example, can eat the tuber either dried or directly from the ground or the green plant biomass (stalks and leaves) from the pasture. Washed Jerusalem artichoke tubers can be fed to many animals, and silage produced from the harvested stalks and leaves. The silage has high nutrient values and satisfactory digestion performance for ruminants. Its high inulin content beneficially affects the rumen metabolism and microflora. However, cutting the tops to produce silage greatly reduces the harvest of the tubers. There are also many other Jerusalem artichoke products on the market, such as supplementary feed for horses, dogs, and small animals.
South Korean president Lee Jae Myung criticized the campaign via X, stating that it insulted the victims and the residents of Gwangju. Starbucks Korea apologized and its CEO, Son Jeong-Hyun, was fired. Starbucks Korea planned to shutter all its stores in South Korea for half a day on June 22 for its staff to attend a history lesson to increase historical awareness and social sensitivities.
Sources: en.wikipedia.org
No. Thymosin beta-4 is a 43-residue protein, while TB-500 matches only residues 17 to 23 of that chain. The two are related but differ in size, and a method that identifies one does not automatically identify the other.
It corresponds to the actin-binding region of thymosin beta-4. Commercial synthesis reproduces that seven-residue stretch, usually with an acetyl group on the N-terminus.
It is not authorised as a medicine in the United States or the European Union and is distributed as a research chemical. Labels consequently carry research-use-only statements rather than clinical indications.
Sealed, dry and protected from light at reduced temperature is the usual laboratory convention. Allowing a cold vial to reach room temperature before opening limits condensation. Repeated opening exposes the powder to moisture and should be minimised.