If you have been reading about reversed-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.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
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.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
| 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 |
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.
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.
The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
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.
Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
=== Discovery and synthesis of promethium metal === Promethium was first produced and characterized at Oak Ridge National Laboratory (Clinton Laboratories at that time) in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin and Charles D. Coryell by separation and analysis of the fission products of uranium fuel irradiated in the graphite reactor; however, being too busy with military-related research during World War II, they did not announce their discovery until 1947. The original proposed name was "clintonium", after the laboratory where the work was conducted; however, the name "prometheum" was suggested by Grace Mary Coryell, the wife of one of the discoverers. It is derived from Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to humans and symbolizes "both the daring and the possible misuse of the mankind intellect". The spelling was then changed to "promethium", as this was in accordance with most other metals.
=== Violent Crime and Law Enforcement Act === Clinton signed the 1994 Crime Bill, which was written by Senator Joe Biden of Delaware. It included 30 billion dollars' worth of federal anticrime funding. Specific to the war on drugs, Clinton included the three-strikes law, which required a mandatory life sentence for any felony violent crime conviction after two other prior convictions. Some social justice critics argue that the law disproportionately affected criminals in urban neighborhoods hurt by policing the war on drugs, rather than white-collar criminals. The bill also authorized $16 million in new funding for the development of federal prisons and state and local police forces. The Justice Policy Institute stated in 2008 that the administration's "tough on crime" policies caused larger increases in federal and state inmate populations than for any other president in American history. The act also saw the expansion of the federal death penalty. Sixty new capital punishment charges were created including non-homicidal narcotics offenses, drive-by shootings resulting in death, and carjackings relating to death. Between 1994 and 1999, nearly two thirds of people sentenced to the federal death penalty were black during Clinton's presidency, nearly seven times that of their representation in the US population. During his two terms, the federal prison population increased from 1.3 million to 2 million inmates. The law featured a provision that removed the approval of Pell Grants for low-income inmates in federal prison.
India Archived 11 January 2021 at the Wayback Machine. The World Factbook. Central Intelligence Agency. India web resources provided by GovPubs at the University of Colorado Boulder Libraries India from BBC News Wikimedia Atlas of India Geographic data related to India at OpenStreetMap Key Development Forecasts for India from International Futures
Connective tissue disorders predispose women to developing cystocele and other pelvic organ prolapses. The tissues tensile strength of the vaginal wall decreases when the structure of the collagen fibers change and become weaker.
== Function == The enzyme catalyses a chemical reaction that produces a specific isomer of cyclic guanosine monophosphate–adenosine monophosphate (cGAMP) from the components guanosine triphosphate (GTP) and adenosine triphosphate (ATP), with two units of pyrophosphate (PPi) as a byproduct:
Sources: en.wikipedia.org
Parliamentary elections were held in Portugal on 29 January 1922. The Democratic Party emerged as the largest in Parliament, winning 74 of the 163 seats in the House of Representatives and 37 of the 70 seats in the Senate.
Beginning in the 1950s, The Walt Disney Company began producing made-for-television films in their long-running anthology series Disneyland (later to be popularly known as The Wonderful World of Color and The Wonderful World of Disney). Many of Disney's TV movies were miniseries that aired in installments over several weeks, and a few (such as Davy Crockett and The Scarecrow of Romney Marsh) were later re-edited and released theatrically. During the 1980s, in addition to films made for their weekly TV series, Disney began making original films for their television network, The Disney Channel. After the acquisition of ABC in the 1990s, Disney began co-producing uncharacteristic films (Stephen King's Storm of the Century, Home Alone 4) as well as TV reunion movies (The Facts of Life Reunion, The Growing Pains Movie) and a few in conjunction with Hallmark Entertainment (Dinotopia, Mr. St. Nick, Snow White: The Fairest of Them All).
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===== Parity Violation ===== Parity, a physical property of symmetry, is conserved for strong, electromagnetic, and gravitational interactions. However, experimental work involving weak forces, such as the interactions between subatomic particles, found that parity is not conserved in these interactions (see Parity Violation). This theoretically would result in slight energy differences between mirror-image enantiomers of a single compound, which could cause a small stereochemical bias for the lower-energy enantiomer. However, a definitive relationship between molecular chirality and parity-violating energy differences have not yet been experimentally demonstrated.
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.
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.