A practical reference on freeze-thaw cycle: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-08-16 and is reviewed periodically as new material appears.
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not a steroid, peptide, or natural hormone. In scientific literature, it appears under the code SR9009 and in non-scientific contexts as Stenabolic. The compound was identified through chemical screening efforts aimed at targeting circadian clock components. Its status remains investigational, and no regulatory agency has approved it as a human medicine.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or lower | Desiccated and protected from light |
| Common analytical method | LC-MS/MS | Detects parent drug and metabolites |
| Solubility class | Lipophilic; soluble in organic solvents | Low aqueous solubility |
| Molecular weight | 437.94 g/mol | Calculated from reported formula |
| Synonyms | SR9009; REV-ERB agonist | Code name used in scientific literature |
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
Identity and purity testing for SR9009 commonly uses liquid chromatography coupled with tandem mass spectrometry. This method separates the compound from matrix components and detects it by mass-to-charge transitions, providing sensitive and specific confirmation. Nuclear magnetic resonance spectroscopy can support structural identification, while high-performance liquid chromatography with ultraviolet detection may estimate purity. Because online products labeled as SR9009 may contain other substances or no active compound at all, independent verification is important in research settings. Certificates of analysis are useful but not a substitute for in-house testing.
Laboratory samples of SR9009 are typically supplied as a white to off-white powder. The compound dissolves readily in organic solvents such as dimethyl sulfoxide and ethanol, while its solubility in water is low. Because of this solubility profile, researchers often prepare concentrated stock solutions in an organic solvent before diluting them into aqueous assay buffers. Light exposure, moisture, and repeated freeze-thaw cycles can degrade many small molecules, so handling procedures usually aim to minimize these factors. Purity is commonly checked before use.
Storage conditions for research-grade SR9009 generally involve a freezer at approximately minus twenty degrees Celsius, sometimes lower for long-term preservation. Containers should remain tightly closed and protected from light. Desiccants may be used to limit moisture uptake. Solutions are often stored in aliquots to avoid repeated warming and cooling. Stability data for the compound under various conditions are limited, so laboratories typically follow supplier recommendations and verify performance through periodic analytical checks rather than assuming indefinite stability.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
=== Diagnostic use === Immunohistochemistry using antibodies to ubiquitin can identify abnormal accumulations of this protein inside cells, indicating a disease process. These protein accumulations are referred to as inclusion bodies (which is a general term for any microscopically visible collection of abnormal material in a cell). Examples include:
Film has been the most influential medium in the presentation of the history of slavery to the general public around the world. The American film industry has had a complex relationship with slavery and until recent decades often avoided the topic. Films such as The Birth of a Nation (1915) and Gone with the Wind (1939) became controversial because they gave a favourable depiction. In 1940 The Santa Fe Trail gave a liberal but ambiguous interpretation of John Brown's attacks on slavery. The Civil Rights Movement in the 1950s made defiant slaves into heroes. The question of slavery in American memory necessarily involves its depictions in feature films. Most Hollywood films used American settings, although Spartacus (1960), dealt with an actual revolt in the Roman Empire known as the Third Servile War. The revolt failed, and all the rebels were executed, but their spirit lived on according to the film. Spartacus stays surprisingly close to the historical record. The Last Supper (La última cena in Spanish) was a 1976 film directed by Cuban Tomás Gutiérrez Alea about the teaching of Christianity to slaves in Cuba, and emphasizes the role of ritual and revolt. Burn! takes place on the imaginary Portuguese island of Queimada (where the locals speak Spanish) and it merges historical events that took place in Brazil, Cuba, Santo Domingo, Jamaica, and elsewhere.
== Chemicals in agriculture == According to the Thai government's The Eleventh National Economic and Social Development Plan (2012-1016), Thailand is number one in the world in the application of chemicals in agriculture. The report stated, "The use of chemicals in the agricultural and industrial sectors is growing while control mechanisms are ineffective making Thailand rank first in the world in the use of registered chemicals in agriculture."
Surgical technique – the septal mucosal flap The surgeon cuts the anteriorly based septal mucosal tissue-flap as widely as possible, and then releases it with a low, posterior back-cut; but only as required to allow the rotation of the tissue-flap into the nasal wound.
=== Neurodegeneration === Several studies in cell and invertebrate models of Parkinson's disease (PD) and Huntington's disease (HD) suggested potential neuroprotective effects of SIRT2 inhibition, in striking contrast with other sirtuin family members. In addition, recent evidence shows that inhibition of SIRT2 protects against MPTP-induced neuronal loss in vivo.
Sources: en.wikipedia.org
Catalytic efficiency: Fusion of certain peptides allow for greater catalytic efficiency by altering the tertiary and quaternary structure of the target protein. Solubility: A common challenge in fusion protein design is the issue of insolubility of newly synthesized fusion proteins in the recombinant host, leading to an over-aggregation of the target protein in the cell. Molecular chaperones that are able to aid in protein folding may be added, thereby better segregating hydrophobic and hydrophilic interactions in the solute to increase protein solubility. Thermostability: Singular peptides or protein fragments are typically added to reduce flexibility of either the N or C terminus of the target protein, which reinforces thermostability and stabilizes pH range. Enzyme activity: Fusion that involves the introduction of hydrogen bonds may be used to expand overall enzyme activity. Expression levels: Addition of numerous fusion fragments, such as maltose binding protein (MBP) or small ubiquitin-like molecule (SUMO), serve to enhance enzyme expression and secretion of the target protein. Immobilization: PHA synthase, an enzyme that allows for the immobilization of proteins of interest, is an important fusion tag in industrial research. Crystal quality: Crystal quality can be improved by adding covalent links between proteins, aiding in structure determination techniques.
==== Metal-based nanoparticles ==== Inorganic nanomaterials, (e.g. quantum dots, nanowires, and nanorods) because of their interesting optical and electrical properties, could be used in optoelectronics. Furthermore, the optical and electronic properties of nanomaterials which depend on their size and shape can be tuned via synthetic techniques. There are the possibilities to use those materials in organic material based optoelectronic devices such as organic solar cells, OLEDs etc. The operating principles of such devices are governed by photoinduced processes like electron transfer and energy transfer. The performance of the devices depends on the efficiency of the photoinduced process responsible for their functioning. Therefore, better understanding of those photoinduced processes in organic/inorganic nanomaterial composite systems is necessary in order to use them in optoelectronic devices. Nanoparticles or nanocrystals made of metals, semiconductors, or oxides are of particular interest for their mechanical, electrical, magnetic, optical, chemical and other properties. Nanoparticles have been used as quantum dots and as chemical catalysts such as nanomaterial-based catalysts. Recently, a range of nanoparticles are extensively investigated for biomedical applications including tissue engineering, drug delivery, biosensor. Nanoparticles are of great scientific interest as they are effectively a bridge between bulk materials and atomic or molecular structures.
== P == Paracelsus (1493–1541), alchemist Rudolph Pariser (1923–2021), theoretical and organic chemist Robert G. Parr (1921–2017), theoretical chemist Louis Pasteur (1822–1895), French biochemist, father of pasteurization Linus Pauling (1901–1994), Nobel Prizes in chemistry and peace Charles J. Pedersen (1904–1989), 1987 Nobel Prize in Chemistry Eugène-Melchior Péligot (1811–1890), French chemist who isolated the uranium metal William Henry Perkin (1838–1907), British organic chemist and inventor of mauveine (dye) William Henry Perkin, Jr. (1860–1929), British organic chemist, son of Sir William Henry Perkin Max Perutz (1914–2002), 1962 Nobel Prize in Chemistry Eva Philbin (1914–2005), Irish chemist David Andrew Phoenix (born 1966), British biochemist Georgy Pigulevsky (1888–1964), Russian chemist and biochemist James Pitts (1921–2014), American chemist known for work on photochemistry and atmospheric chemistry Roy J. Plunkett (1910–1994), discoverer of Teflon John Charles Polanyi (born 1929), Canadian chemist, Nobel Prize in Chemistry 1986 John A.
Lithium toxicity, which is also called "lithium overdose" or "lithium poisoning", is the condition of having too much lithium in the blood. This condition also happens in persons who are taking lithium in which the lithium levels are affected by drug interactions in the body. Lithium toxicity occurs at levels above 1.5 mmol/L. Lithium levels above 2.0 mmol/L can lead to disorientation, renal failure, seizures, and coma. Above 2.0 mmol/L, acute renal failure can occur, and kidney dialysis may be used. In the elderly, signs of toxicity can occur at half the levels of younger patients. In acute toxicity, people have primarily gastrointestinal symptoms such as vomiting and diarrhea, which may result in volume depletion. During acute toxicity, lithium distributes later into the central nervous system resulting in mild neurological symptoms, such as dizziness. In chronic toxicity, people have primarily neurological symptoms which include nystagmus, tremor, hyperreflexia, ataxia, and change in mental status. During chronic toxicity, the gastrointestinal symptoms seen in acute toxicity are less prominent. The symptoms are often vague and nonspecific. If the lithium toxicity is mild or moderate, lithium dosage is reduced or stopped entirely. If the toxicity is severe, lithium may need to be removed from the body.
=== Jondeung et al. (2012) === Another molecular study (of mitochondrial genomes), conducted in 2012 by Jondeung et al., strongly support monophyletic Pancrustacea and places Malacostraca + Entomostraca and Branchiopoda as the sister clade to Hexapoda and places Cirripedia + Remipedia as sister to the rest of Pancrustacea.
Sources: en.wikipedia.org
Played in his 52nd Masters Tournament at Augusta National in April 2009, extending his record of for most Masters appearances Inducted into the African American Sports Hall of Fame in May 2007, with Lifetime Achievement Award Has played in a record 46 consecutive British Open Championships, winning 3 times over 3 decades. Stars with Camilo Villegas in a MasterCard "priceless foursome" television commercial launched during the U.S. Open in June 2009 In November 2009 he was awarded the inaugural Breeders Cup "Sports and Racing Excellence Award" at Santa Anita Park in California which honours owners and breeders of thoroughbred race horses. Was inducted into the Asian Pacific Golf Hall of Fame with Jack Nicklaus in 2011 at a ceremony in Pattaya, Thailand. In December 2011, Gary Player Design was selected amongst the finalists to design the golf course for the 2016 Olympic Games in Rio de Janeiro He received the PGA Tour Lifetime Achievement Award at The Players Championship in May 2012. The first international person to receive this accolade. Received the 2020 GCSAA Old Tom Morris Award from the Golf Course Superintendents Association of America Received the Presidential Medal of Freedom on 7 January 2021 from then President Donald Trump. With the death of Jack Burke Jr., Player becomes the oldest living Masters champion.
Believing that Gary, the Nosferatu chief, has stolen the sarcophagus, the fledgling is sent to Hollywood to find him; after locating a captured Nosferatu for Gary, he reveals that the Giovanni vampire clan stole the sarcophagus. The fledgling infiltrates the Giovanni mansion and finds the sarcophagus guarded by the Kuei-Jin, who claim their leader, Ming-Xiao, has allied with LaCroix. The locked sarcophagus is returned to LaCroix's tower, and Beckett, a vampire scholar, tells the fledgling that the only person who can open it has been abducted by Bach to lure LaCroix. The fledgling kills Bach and learns that the sarcophagus's key has been stolen. The fledgling returns to LaCroix, learning that the Sabbat tried to steal the sarcophagus to destroy it and prevent Gehenna, then kills the Sabbat leader to disperse his followers. The fledgling is met by Ming-Xiao, who offers an alliance. Ming-Xiao reveals that she has the key, and LaCroix killed Grout to prevent his powerful insight from unveiling LaCroix's plans; Ming-Xiao disguised herself as Nines at the mansion to frame him. Denying Ming-Xiao's claims, LaCroix rescinds the blood hunt on Nines and entrusts the fledgling with recruiting the anarchs to punish the Kuei-Jin for murdering Grout. The fledgling finds Nines hiding in Griffith Park, and they are then attacked by a werewolf, and Nines is badly injured. The fledgling escapes with Jack, who reveals that LaCroix has issued an execution order on the fledgling for framing Nines on Ming-Xiao's orders.
== External links == "Parathyroid Hormone Receptors: PTH2". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2008-12-09. Receptor,+Parathyroid+Hormone,+Type+2 at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
== Dissolution == On 25 October 2021, in the 2021 Sudan coup d'état, Chairman Abdel Fattah al-Burhan dissolved the Council and removed Prime Minister Abdalla Hamdok from office. He re-formed the TSC with new membership on November 11, 2021. On November 21, 2021, al-Burhan signed a deal with Hamdok that reinstated him as prime minister, provided for the release of all political prisoners detained in the coup, and restored the 2019 Draft Constitutional Declaration.
== Uses == Benzene is used mainly as an intermediate to make other chemicals, above all ethylbenzene (and other alkylbenzenes), cumene, cyclohexane, and nitrobenzene. In 1988, it was reported that two-thirds of all chemicals on the American Chemical Society's lists contained at least one benzene ring. More than half of the entire benzene production is processed into ethylbenzene, a precursor to styrene, which is used to make polymers and plastics like polystyrene. Some 20% of the benzene production is used to manufacture cumene, which is needed to produce phenol and acetone for resins and adhesives. Cyclohexane consumes around 10% of the world's benzene production; it is primarily used in the manufacture of nylon fibers, which are processed into textiles and engineering plastics. Smaller amounts of benzene are used to make some types of rubbers, lubricants, dyes, detergents, drugs, explosives, and pesticides. In 2013, the biggest consumer country of benzene was China, followed by the USA. Benzene production is currently expanding in the Middle East and in Africa, whereas production capacities in Western Europe and North America are stagnating. Toluene is now often used as a substitute for benzene, for instance as a fuel additive. The solvent-properties of the two are similar, but toluene is less toxic and has a wider liquid range. Toluene is also processed into benzene.
Sources: en.wikipedia.org
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.
Research samples are typically kept frozen, desiccated, and protected from light. Stock solutions are often aliquoted to reduce freeze-thaw cycles.
High-performance liquid chromatography and nuclear magnetic resonance are standard for purity and identity. Mass spectrometry confirms molecular weight.
It is a synthetic compound studied as an agonist of REV-ERB nuclear receptors. It is not an approved medicine and has mainly been examined in laboratory and animal research.