The short version of DAC fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-05 and is reviewed periodically as new material appears.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
Reverse-phase high-performance liquid chromatography is the standard tool for purity assessment. The technique separates the target peptide from truncated or modified byproducts. Mass spectrometry confirms molecular weight and supports sequence verification. Electrospray ionization and matrix-assisted laser desorption are both used. Amino acid analysis provides an independent check on composition. Purity values are commonly reported as area percentage from the chromatogram. Residual trifluoroacetate and water content are also measured in many quality programs.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
At the pituitary, the peptide binds the growth hormone-releasing hormone receptor on somatotroph cells. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone. Somatostatin and other hypothalamic signals modulate this response. Negative feedback from insulin-like growth factor 1 also influences output. The same regulatory architecture operates with the native hormone. Whether the synthetic analog alters feedback dynamics over repeated exposure remains an open question. Most published receptor work uses cell models rather than intact human systems.
CJC-1295 is a synthetic peptide belonging to the growth hormone-releasing hormone analog family. It comprises twenty-nine amino acid residues derived from the N-terminal region of natural GHRH. The molecule incorporates several non-natural substitutions that increase resistance to enzymatic degradation. These modifications extend its activity compared with the native hormone fragment. Researchers use it to study pituitary growth hormone secretion in laboratory and clinical settings. This compound is distinct from native GHRH in its stability profile.
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
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.
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.
CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.
Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.
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.
Episcleritis is a benign, self-limiting inflammatory disease affecting part of the eye called the episclera. The episclera is a thin layer of tissue that lies between the conjunctiva and the connective tissue layer that forms the white of the eye (sclera). Episcleritis is a common condition, and is characterized by the abrupt onset of painless eye redness. There are two types of episcleritis, nodular and simple. Nodular episcleritis lesions have raised surface. Simple episcleritis lesions are flat. There are two subtypes. In diffuse simple episcleritis, inflammation is generalized. In sectoral simple episcleritis, the inflammation is restricted to one region. Most cases of episcleritis have no identifiable cause, although about a third of cases are associated with various systemic diseases. Often people with episcleritis experience it recurrently. Treatment focuses on decreasing discomfort, and includes lubricating eye drops. More severe cases may be treated with topical corticosteroids or oral anti-inflammatory medications (NSAIDs).
(3) Post- synthetic modification of MOFs increased their functionality by reacting organic units and metal-organic complexes with linkers. (4) Multifunctional MOFs incorporated multiple functionalities in a single framework. Since ligands in MOFs typically bind reversibly, the slow growth of crystals often allows defects to be redissolved, resulting in a material with millimeter-scale crystals and a near-equilibrium defect density. Solvothermal synthesis is useful for growing crystals suitable to structure determination, because crystals grow over the course of hours to days. However, the use of MOFs as storage materials for consumer products demands an immense scale-up of their synthesis. Scale-up of MOFs has not been widely studied, though several groups have demonstrated that microwaves can be used to nucleate MOF crystals rapidly from solution. This technique, termed "microwave-assisted solvothermal synthesis", is widely used in the zeolite literature, and produces micron-scale crystals in a matter of seconds to minutes, in yields similar to the slow growth methods. Some MOFs, such as the mesoporous MIL-100(Fe), can be obtained under mild conditions at room temperature and in green solvents (water, ethanol) through scalable synthesis methods. A solvent-free synthesis of a range of crystalline MOFs has been described. Usually the metal acetate and the organic proligand are mixed and ground up with a ball mill. Cu3(BTC)2 can be quickly synthesised in this way in quantitative yield.
== Nomenclature == Arrhenius acids are named according to their anions. In the classical naming system, the ionic suffix is dropped and replaced with a new suffix, according to the table following. The prefix "hydro-" is used when the acid is made up of just hydrogen and one other element. For example, HCl has chloride as its anion, so the hydro- prefix is used, and the -ide suffix makes the name take the form hydrochloric acid. Classical naming system:
Ion mobility spectrometry (IMS) is a method of conducting analytical research that separates and identifies ionized molecules present in the gas phase based on the mobility of the molecules in a carrier buffer gas. Even though it is used extensively for military or security objectives, such as detecting drugs and explosives, the technology also has many applications in laboratory analysis, including studying small and big biomolecules. IMS instruments are extremely sensitive stand-alone devices, but are often coupled with mass spectrometry (MS), gas chromatography or high-performance liquid chromatography (HPLC) in order to achieve a multi-dimensional separation. They come in various sizes, ranging from a few millimetres to several metres depending on the specific application, and are capable of operating under a broad range of conditions. IMS instruments such as microscale high-field asymmetric-waveform ion mobility spectrometry can be palm-portable for use in a range of applications including volatile organic compound (VOC) monitoring, biological sample analysis, medical diagnosis and food quality monitoring. Systems operated at higher pressure (i.e. atmospheric conditions, 1 atm or 1013 hPa) are often accompanied by elevated temperature (above 100 °C), while lower pressure systems (1–20 hPa) do not require heating.
Sources: en.wikipedia.org
These medications may suppress appetite, make food taste different, or affect how nutrients are absorbed, making it even less likely seniors will get the required nutrients. 8% of seniors suffer from hyponatremia, although it is unclear how much of that is due to "tea and toast" diets. The prevalence of hyponatremia in the elderly population may be even higher in health care settings. Hyponatremia is believed to arise as a result of a diet poor in salt and protein with large water intake in combination with a low glomerular filtration rate (GFR). The low GFR causes a lowered rate of osmole excretion, and an increase in the amount of water reabsorbed; thus, hyponatremia occurs when the amount of water intake exceeds the renal water excretion capacity. Medications, such as thiazides and antidepressants, may exacerbate symptoms of hyponatremia.
More related to its alcohol dehydrogenase activity, GSNOR null mice show a 30% reduction in the LD50 for formaldehyde and a decreased capacity to metabolize retinol, although it is clear from these studies that other pathways exist for the metabolism of these compounds.
A documentary film (often called simply a documentary) is a nonfiction motion picture intended to "document reality, primarily for instruction, education or maintaining a historical record". The American author and media analyst Bill Nichols has characterized the documentary in terms of "a filmmaking practice, a cinematic tradition, and mode of audience reception [that remains] a practice without clear boundaries". Research into information gathering, as a behavior, and the sharing of knowledge, as a concept, has noted how documentary movies were preceded by the notable practice of documentary photography. This has involved the use of singular photographs to detail the complex attributes of historical events and continues to a certain degree to this day, with an example being the conflict-related photography achieved by popular figures such as Mathew Brady during the American Civil War. Documentary movies evolved from the creation of singular images in order to convey particular types of information in depth, using film as a medium. Early documentary films, originally called "actuality films", briefly lasted for one minute or less in most cases. While faithfully depicting true events, these releases possessed no narrative structure per se and were of limited interest. Over time, documentaries have evolved to become longer in length and to include more categories of information. Some examples are explicitly educational, while others serve as observational works; docufiction movies notably include aspects of dramatic storytelling that are clearly fictional.
The enzyme glucose oxidase (GOx) converts glucose into gluconic acid and hydrogen peroxide while consuming oxygen. Another enzyme, peroxidase, catalyzes a chromogenic reaction (Trinder reaction) of phenol with 4-aminoantipyrine to a purple dye.
Pompe disease has an autosomal recessive inheritance pattern. This means the defective gene is located on an autosome, and two faulty copies of the gene—one from each parent—are required to be born with the disorder. As with all cases of autosomal recessive inheritance, children have a one in four chance of inheriting the disorder when both parents carry the defective gene, and although both parents carry one copy of the defective gene, they are usually unaffected by the disorder. The disease is caused by a mutation in a gene (acid alpha-glucosidase: also known as acid maltase) on the long arm of chromosome 17 at 17q25.2-q25.3 (base pair 75,689,876 to 75,708,272). The number of mutations described is currently (in 2010) 289 with 67 being non-pathogenic mutations and 197 pathogenic mutations. The remainder are still being evaluated for their association with disease. The gene spans approximately 20 kb and contains 20 exons with the first exon being noncoding. The coding sequence of the putative catalytic site domain is interrupted in the middle by an intron of 101 bp. The promoter has features characteristic of a housekeeping gene. The GC content is high (80%) and distinct TATA and CCAAT motifs are lacking. Most cases appear to be due to three mutations. A transversion (T → G) mutation is the most common among adults with this disorder. This mutation interrupts a site of RNA splicing. The gene encodes a protein—acid alpha-glucosidase (EC 3.2.1.20)—which is a lysosomal hydrolase.
Sources: en.wikipedia.org
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
The powder is normally held at minus twenty degrees Celsius or below. Light and moisture exposure should be minimized. Repeated warming and cooling cycles are avoided.