This is a working overview of certificate of analysis, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-05 and is reviewed periodically as new material appears.
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.
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.
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.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
| Property | Value | Notes |
|---|---|---|
| Synonyms | SR9009; Stenabolic | Stenabolic is an informal name |
| Common form | Crystalline powder | Supplied in milligram to gram quantities |
| Long-term storage | -20 °C, desiccated, protected from light | Reduces degradation |
| Detection technique | LC-MS/MS | Common in anti-doping and research analysis |
| Regulatory status | Prohibited in sport by WADA | Not approved for human therapeutic use |
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
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.
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.
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.
dihydrothymine dehydrogenase dihydrouracil dehydrogenase (NADP+) 4,5-dihydrothymine: oxidoreductase DPD DHPDH dehydrogenase, dihydrouracil (nicotinamide adenine dinucleotide, phosphate) DHU dehydrogenase hydropyrimidine dehydrogenase dihydropyrimidine dehydrogenase (NADP+)
The hydrophobic effect can be quantified by measuring the partition coefficients of non-polar molecules between water and non-polar solvents. The partition coefficients can be transformed to free energy of transfer which includes enthalpic and entropic components, ΔG = ΔH - TΔS. These components are experimentally determined by calorimetry. The hydrophobic effect was found to be entropy-driven at room temperature because of the reduced mobility of water molecules in the solvation shell of the non-polar solute; however, the enthalpic component of transfer energy was found to be favorable, meaning it strengthened water-water hydrogen bonds in the solvation shell due to the reduced mobility of water molecules. At the higher temperature, when water molecules become more mobile, this energy gain decreases along with the entropic component. The hydrophobic effect depends on the temperature, which leads to "cold denaturation" of proteins. The hydrophobic effect can be calculated by comparing the free energy of solvation with bulk water. In this way, the hydrophobic effect not only can be localized but also decomposed into enthalpic and entropic contributions.
== Sources == L. S. Ettre (2004) American Laboratory, May 2004, pages 4-6 In memoriam: Csaba Horváth A. Guttman (2000) American Laboratory, June 2000, pages 6-10 Archived 2022-05-20 at the Wayback Machine Happy Birthday Csaba Horváth The Hungary Page Nobel Prize Winners and Famous Hungarians: Science, Mathematics & Technology Yale news of his death at the Wayback Machine (archived June 17, 2004) "Speeches at his remembrance Service". Archived from the original on June 18, 2004. Retrieved September 13, 2007. Claudia Flavell-White The Chemical Engineer October 2010 pp 54–55 "Degrees of Separation: Chemical Engineers who Changed the World - Csaba Horváth" An Introduction to Separation Science, (1973) B.L. Karger, Cs. Horváth and L.R. Snyder, Wiley
If a protein was introduced that increased the integrity of its parent bubble, then that bubble had an advantage. Primitive reproduction may have occurred when the bubbles burst, releasing the results of the experiment into the surrounding medium. Once enough of the right compounds were released into the medium, the development of the first prokaryotes, eukaryotes, and multi-cellular organisms could be achieved. However, the first cell membrane could not have been composed of phospholipids due its low permeability, as ions would not able to pass through the membrane. Rather it is suggested they were composed of fatty acids, as they can freely exchange ions, allowing geochemically sustained proton gradients at alkaline hydrothermal vents that might lead to prebiotic chemical reactions via CO2 fixation.
=== Calculations === Using the known temperature of the sample, the bottle volume, the concentrations of gas in the headspace (as determined by GC), and Henry's law constant, the concentration of the original water sample is calculated. Total gas concentration (TC) in the original water sample is calculated by determining the concentration of headspace and converting this to the partial pressure and then solving for the aqueous concentration which partitioned in the gas phase (CAH) and the concentration remaining in the aqueous phase (CA). The total concentration of gas in original sample (TC) is the sum of the concentration partitioned in the gas phase (CAH) and the concentration remaining in the aqueous phase (CA):
Sources: en.wikipedia.org
=== Season 1 Re-edited for Syndication (1976-77) === The 6 original 60-minute episodes of season 1 were combined into 3 new episodes for syndication. Some material was cut and some linking voice-overs were added. Directors and Writers are shown as they appear in the on-screen credits. "Matthew Howard" is reportedly a pseudonym for Douglas Heyes, who wrote the original episode 1.
The core structure of immunoliposomes is a lipid bilayer. This lipid bilayer forms a hydrophilic core, which provides stable encapsulation for a therapeutic payload. Common lipids used are phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cholesterol. The lipid bilayer is surface modified through conjugation using monoclonal antibodies for specific recognition of the target cells or tissues of interest. The core of the immunoliposome contains the therapeutic payload, which can be anything from small drugs, nucleic acids, peptides, or imaging agents. There are often stabilizers and excipients present for formulation, stability, and functionality. Some include polyethylene glycol (PEG), antioxidants to prevent degradation of lipids, and buffering agents for optimal pH.
=== Slowing circadian oscillations === Deuterium has been shown to lengthen the period of oscillation of the circadian clock when dosed in rats, hamsters, and Gonyaulax dinoflagellates. In rats, chronic intake of 25% 2H2O disrupts circadian rhythm by lengthening the circadian period of suprachiasmatic nucleus-dependent rhythms in the brain's hypothalamus. Experiments in hamsters also support the theory that deuterium acts directly on the suprachiasmatic nucleus to lengthen the free-running circadian period.
Urea derivatives on the market are Regorafenib and Sorafenib. The urea derivatives block the VEGFR and/or one or more protein kinases and can therefore modulate, regulate and/or inhibit tyrosine kinase signal transduction. Increased stability against degradation by liver enzymes can be acquired by adding a deuterium to heterocyclic compounds. Novel urea compounds with pentafluoro-sulfane substitute on a phenyl group show better protein kinase inhibition in diseases like cancer when compared to aryl-urea compounds with either quinazoline or pyrimidine moieties. N-substituted phenyl N’-substituted heterocyclic urea compounds give an IC50 between 15 nM and 1 μM for VEGFR-2. Having a 1H-indole-1-carboxamide scaffold on aryl-urea compounds results in added VEGFR-2 potency and selectivity and gives an IC50 of 3nM against the receptor.
=== Chemical === Copernicium is the tenth and last member of the 6d series and is the heaviest group 12 element in the periodic table, below zinc, cadmium and mercury. It is predicted to differ significantly from the lighter group 12 elements. The valence s-subshells of the group 12 elements and period 7 elements are expected to be relativistically contracted most strongly at copernicium. This and the closed-shell configuration of copernicium result in it probably being a very noble metal. A standard reduction potential of +2.1 V is predicted for the Cn2+/Cn couple. Copernicium's predicted first ionization energy of 1155 kJ/mol almost matches that of the noble gas xenon at 1170.4 kJ/mol. Copernicium's metallic bonds should also be very weak, possibly making it extremely volatile like the noble gases, and potentially making it gaseous at room temperature. However, it should be able to form metal–metal bonds with copper, palladium, platinum, silver, and gold; these bonds are predicted to be only about 15–20 kJ/mol weaker than the analogous bonds with mercury. In opposition to the earlier suggestion, ab initio calculations at the high level of accuracy predicted that the chemistry of singly-valent copernicium resembles that of mercury rather than that of the noble gases. The latter result can be explained by the huge spin–orbit interaction which significantly lowers the energy of the vacant 7p1/2 state of copernicium. Once copernicium is ionized, its chemistry may present several differences from those of zinc, cadmium, and mercury.
Sources: en.wikipedia.org
Mast cells play a key role in the inflammatory process. Histamine dilates post-capillary venules, activates the endothelium, and increases blood vessel permeability. This leads to local edema (swelling), warmth, redness, and the attraction of other inflammatory cells to the site of release. It also depolarizes nerve endings (leading to itching or pain). Cutaneous signs of histamine release are the "flare and wheal" reaction. The bump and redness immediately following a mosquito bite are a good example of this reaction, which occurs seconds after challenge of the mast cell by an allergen.
In 1872, Russian Alexander Lodygin invented an incandescent light bulb and obtained a Russian patent in 1874. He used as a burner two carbon rods of diminished section in a glass receiver, hermetically sealed, and filled with nitrogen, electrically arranged so that the current could be passed to the second carbon when the first had been consumed. Later he lived in the US, changed his name to Alexander de Lodyguine and applied for and obtained patents for incandescent lamps having chromium, iridium, rhodium, ruthenium, osmium, molybdenum and tungsten filaments. On 24 July 1874, a Canadian patent was filed by Henry Woodward and Mathew Evans for a lamp consisting of carbon rods mounted in a nitrogen-filled glass cylinder. They were unsuccessful at commercializing their lamp, and sold rights to their patent to Thomas Edison in 1879. (Edison needed ownership of the novel claim of lamps connected in a parallel circuit.) The government of Canada maintains that it is Woodward and Evans who invented the lightbulb.
A common criticism of both the PDCAAS and the DIAAS is that calculating the PDCAAS/DIAAS of a diet solely based on the PDCAAS/DIAAS of the individual constituents is misleading, because one food may provide an abundance of an amino acid that the other is missing, in which case the PDCAAS/DIAAS of the diet is higher than that of any one of the constituents. To arrive at the final result, all individual amino acids would have to be taken into account, so the protein quality of each constituent would be superfluous. For example, various cereals have protein qualities between 0.4 and 0.8 and are generally limited by lysine, but contain more than enough methionine. Legumes, with the exception of soy, generally have protein qualities between 0.5 and 0.8 and are limited by methionine rather than lysine. When eaten together in the optimal ratio, the quality of the combined constituent may be as high as 1.0, because each constituent's protein is complemented by the other. A more extreme example would be the combination of gelatine (which contains virtually no tryptophan and thus has a PDCAAS close to 0) with isolated tryptophan (which, lacking all other essential amino acids, also has a PDCAAS of 0). Despite individual scores of 0, the combination of both in adequate amounts has a positive PDCAAS, with the limiting amino acids isoleucine, threonine, and methionine.
The Journal of Chromatographic Science (JCS) is a peer reviewed academic journal of chromatography. It is published by Oxford University Press. The Journal focuses on research papers describing practical and preparative applications and analytical methods relevant to a broad range of laboratory work. The editors-in-chief are Huba Kalász and Neil Danielson. According to the Journal Citation Reports, the journal has a 2020 impact factor of 1.618.
Sources: en.wikipedia.org
Laboratories commonly use liquid chromatography coupled with mass spectrometry to detect SR9009. The method can identify the compound and estimate concentration in a sample. Detection limits depend on the matrix and instrument.
Research-grade purity indicates a supplier's measured percentage of the intended compound. It does not guarantee safety, sterility, or suitability for human consumption. Buyers should request a certificate of analysis with chromatograms and test methods.
Sports regulators prohibit SR9009 because it is a non-approved substance with potential performance-altering effects. Its presence can be detected in anti-doping testing. Athletes are responsible for substances found in their samples.
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.