If you have been reading about reverse-phase HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-04-08. Numbers and descriptions here follow the published literature rather than marketing material.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C152H252N44O42 | Cited for the form without the drug affinity complex |
| Molecular weight | About 3368 Da | Reported value for modified GRF(1-29) |
| Appearance | White to off-white powder | Lyophilised solid as usually supplied |
| Solubility | Soluble in water and polar solvents | Clarity depends on purity and salt content |
| Typical storage | -20 C or below, dry | Protect from light and repeated warming cycles |
Batch-to-batch consistency depends on solid-phase peptide synthesis and subsequent purification. Coupling efficiency, resin choice, and cleavage conditions all affect the final profile. Counter-ion content and moisture can shift the apparent mass of a batch. Documentation typically includes a certificate of analysis with chromatograms and spectra. Independent verification by a second laboratory is sometimes requested. Whether a given certificate reflects the actual vial contents depends on chain of custody. Analytical methods themselves carry uncertainty that should be stated alongside results.
Lyophilized material is typically stored at minus twenty degrees Celsius or lower. Keeping the vial dry and protected from light preserves peptide integrity. Repeated freeze-thaw cycles can cause aggregation or loss of activity. Once dissolved, solutions are generally kept at two to eight degrees Celsius. Stability data for reconstituted solutions vary, and long-term behavior is not fully established. Working aliquots reduce the number of times a stock container is opened.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
Identity and purity are established with reversed phase high performance liquid chromatography coupled to mass spectrometry. The chromatographic step separates the target peptide from truncated sequences and deletion products, while the mass measurement confirms the expected molecular weight to within a fraction of a dalton. Because the two common variants differ by the presence of the linker, mass alone can distinguish them in the unconjugated state. Amino acid analysis and peptide mapping are used when sequence level confirmation is required.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
Lyophilized peptide powder is comparatively stable when kept dry, cold, and protected from light. Once dissolved, the molecule is vulnerable to deamidation, oxidation, and aggregation, with the rate depending on pH, buffer composition, and temperature. Alkaline conditions and repeated freeze-thaw cycles accelerate loss of the intact peptide. The methionine present in the native sequence is a known oxidation site, which is one reason it was replaced in the modified fragment. Suppliers typically recommend cold storage of solutions and use within a short window.
Analytical confirmation usually relies on reversed-phase high-performance liquid chromatography for purity and on liquid chromatography coupled to mass spectrometry for identity. Mass data reveal the expected molecular mass and can flag truncated or oxidized species. Amino acid analysis and peptide mapping provide sequence-level verification. Immunoassays are used in some biological matrices, but antibodies raised against one releasing-hormone analog may cross-react with another. Reported purity figures depend heavily on the method used, so comparisons between suppliers require matching the analytical approach.
The two variants differ dramatically in how long they persist in circulation. The form lacking the albumin-binding group has a plasma half-life measured in tens of minutes, comparable to the natural hormone fragment. The version carrying the drug affinity complex binds albumin and shows a half-life of roughly six to eight days in human studies. That figure comes from small trials that tracked hormone levels over extended periods. The physiological consequences of sustained versus pulsatile stimulation are still debated and the literature does not settle the point.
Hypersensitivity to methocarbamol or any of the injection components. For the injectable form, suspected kidney failure or renal pathology, due to large content of polyethylene glycol 300 that can increase pre-existing acidosis and urea retention.
== Chemistry and animal toxicology == Buformin hydrochloride is a fine, white to slightly yellow, crystalline, odorless powder, with a weakly acidic bitter taste. Its melting point is 174 to 177 °C, it is a strong base, and is freely soluble in water, methanol and ethanol, but insoluble in chloroform and ether. The log octanol-water partition coefficient (log P) is -1.20E+00 and its water solubility is 7.46E+05 mg/L at 25 °C. Vapor pressure is 1.64E-04 mm Hg at 25 °C (EST); Henry's law constant is 8.14E-16 atm-m3/mole at 25 °C (EST). Its Atmospheric -OH rate constant is 1.60E-10 cm3/molecule-sec at 25 °C.
Pickling in brine is a very common way to use lactic acid fermentation to aid in the preservation of food. Lactic acid bacteria (LAB) already exists as part of the natural flora in most vegetables, so by creating a selective environment of oxygen-poor brine, LAB will dominate in growth and convert sugars to lactic acid. Silage fermentation uses the same principle of creating an anaerobic environment. Different types of LAB will produce different types of silage fermentation.
Later, on April 28, 1950, Joliot-Curie would be dismissed from the military and civilian Atomic Energy Commission for political reasons. Young communist militants (UJRF) were also accused of sabotage actions like the famous Henri Martin affair and the case of Raymonde Dien, who was jailed one year for having blocked an ammunition train, with the help of other militants, in order to prevent the supply of French forces in Indochina in February 1950. The dockworkers across France also struck, in numbers of more than 35,000, in protest of the war. Similar actions against trains occurred in Roanne, Charleville, Marseille, and Paris. Even ammunition sabotage by PCF agents has been reported, such as grenades exploding in the hands of legionaries. These actions became such a cause for concern by 1950 that the French Assembly voted a law against sabotage between March 2–8. At this session tension was so high between politicians that fighting ensued in the assembly following communist deputies' speeches against the Indochinese policy. This month saw the French navy mariner and communist militant Henri Martin arrested by military police and jailed for five years for sabotage and propaganda operations in Toulon's arsenal. On May 5 communist Ministers were dismissed from the government, marking the end of Tripartism. A few months later on November 11, 1950, the French Communist Party leader Maurice Thorez went to Moscow.
=== Protein modification === A classic way to crystalize is by adding a small amount of protease to the droplet, as digestion may yield a more crystallizable fragment by removing unstructured regions. Chemical modification can be used to improve crystallization. The most commonly used is reductive methylation, which changes surface lysines in a way that usually reduces entropy.
Sources: en.wikipedia.org
== In popular culture == The game of Tetris is a puzzle game in which blocks of 4 are adsorbed onto a surface during game play. Scientists have used Tetris blocks "as a proxy for molecules with a complex shape" and their "adsorption on a flat surface" for studying the thermodynamics of nanoparticles.
=== 8 April === Three people were killed and eight others were injured in a Russian missile attack on Zaporizhzhia. One person was killed and five others were injured in Russian air strikes in Sumy Oblast. Two people were killed in separate attacks in Chasiv Yar and Poltava. Ukrainian hackers launched a cyberattack on a data center used by the Russian military, energy, and telecommunications industries, which affected 10,000 enterprises including Gazprom and Lukoil. The SBU arrested a former member of the Party of Regions in Sumy Oblast on suspicion of spying for Russia.
A medical laboratory or clinical laboratory is a laboratory where tests are conducted out on clinical specimens (e.g. Blood, urine, stool, sputum and other body tissues) to obtain information about the health of a patient to aid in diagnosis, treatment, and prevention of disease. Clinical medical laboratories are an example of applied science, as opposed to research laboratories that focus on basic science, such as found in some academic institutions. Medical laboratories vary in size and complexity and so offer a variety of testing services. More comprehensive services can be found in acute-care hospitals and medical centers, where 70% of clinical decisions are based on laboratory testing. Doctors offices and clinics, as well as skilled nursing and long-term care facilities, may have laboratories that provide more basic testing services. Commercial medical laboratories operate as independent businesses and provide testing that is otherwise not provided in other settings due to low test volume or complexity.
In organic chemistry, peptide synthesis is the production of peptides, compounds where multiple amino acids are linked via amide bonds, also known as peptide bonds. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another. Protecting group strategies are usually necessary to prevent undesirable side reactions with the various amino acid side chains. Chemical peptide synthesis most commonly starts at the carboxyl end of the peptide (C-terminus), and proceeds toward the amino-terminus (N-terminus). Protein biosynthesis (long peptides) in living organisms occurs in the opposite direction. The chemical synthesis of peptides can be carried out using classical solution-phase techniques, although these have been replaced in most research and development settings by solid phase methods (see below). Solution phase synthesis retains its usefulness in production of small peptides for industrial purposes. Chemical peptide synthesis facilitates the production of peptides that are difficult to express in bacteria, the incorporation of unnatural amino acids, peptide/protein backbone modification, and the synthesis of peptides containing D-amino acids.
Conversely, venlafaxine robustly inhibited the SERT but only inhibited the NET at high doses. Atomoxetine has been found to act as an NMDA receptor antagonist in rat cortical neurons at therapeutic concentrations (IC50Tooltip half-maximal inhibitory concentration = ~3,000 nM). It causes a use-dependent open-channel block and its binding site overlaps with the Mg2+ binding site. Atomoxetine's ability to increase prefrontal cortex firing rate in anesthetized rats could not be blocked by D1 or α1-adrenergic receptor antagonists, but could be potentiated by NMDA or an α2-adrenergic receptor antagonist, suggesting a glutaminergic mechanism. In Sprague Dawley rats, atomoxetine reduces NR2B protein content without altering transcript levels. Aberrant glutamate and NMDA receptor function have been implicated in the etiology of ADHD. Atomoxetine also reversibly inhibits G protein-coupled inwardly rectifying potassium channel (GIRK) currents in Xenopus oocytes in a concentration-dependent, voltage-independent, and time-independent manner. Kir3.1/3.2 ion channels are opened downstream of M2, α2, D2, and A1 stimulation, as well as other Gi-coupled receptors. Therapeutic concentrations of atomoxetine are within range of interacting with GIRKs, especially in CYP2D6 poor metabolizers. It is not known whether this contributes to the therapeutic effects of atomoxetine in ADHD. It has been found to inhibit voltage-gated sodium channels.
Sources: en.wikipedia.org
It is a synthetic peptide analogue of growth hormone-releasing hormone. Four substitutions in its sequence make it more resistant to enzymatic degradation than the natural hormone. In the version carrying a drug affinity complex, the peptide binds albumin and remains in circulation for days.
No regulatory agency has approved CJC-1295 for clinical use. Human trials were conducted in the 2000s, but the development programme was discontinued before any marketing application succeeded. Material sold today is offered as a research chemical, and its purity depends on the supplier.
Sermorelin is an unmodified fragment of growth hormone-releasing hormone and is cleared quickly. CJC-1295 contains substitutions that resist breakdown, and the form with a drug affinity complex persists much longer. Both act at the same receptor but differ substantially in duration of action.
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.