DAC group comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-09-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off white powder | Typical lyophilized form |
| Water solubility | Soluble | May need a small organic co-solvent |
| Purity assessment | Chromatographic peak area | Most certificates report a percentage figure |
| Storage temperature | Minus 20 C or lower | Dry, dark, sealed container |
| Identity check | Electrospray mass spectrometry | Compared against theoretical mass |
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.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
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.
=== Documentaries === The 2013 documentary Oxyana covers prescription drug abuse in rural Southern West Virginia, based in the town of Oceana and surrounding Wyoming County, specifically highlight the abuse of oxycodone. In 2017, the short documentary film Heroin(e) was released and nominated for the Academy Award for Best Documentary Short Subject at the 90th Academy Awards. The film focuses on the opioid epidemic's effects on Huntington, West Virginia, where the overdose rate was 10 times the US average. In 2020, Netflix released the documentary series The Pharmacist, which covers the efforts of Dan Schneider, a small-town pharmacist in Poydras, Louisiana, to identify his son's killer and his gathering of evidence against a prolific "pill mill" doctor in New Orleans, leading to an investigation against Purdue Pharma's aggressive corporate sales tactics of OxyContin. In 2021, HBO released The Crime of the Century, a 2-part documentary directed by Alex Gibney that follows the opioid epidemic and the political operatives, government regulations and corporations that enable the abuse of opioids, particularly the Sackler family and Purdue Pharma, and received positive reviews." All the Beauty and the Bloodshed is a 2022 documentary about the activist Nan Goldin's fight against the Sackler family for their role in the opioid epidemic in the United States.. At the 95th Academy Awards, the film was nominated for Best Documentary Feature and was awarded a Peabody Award at the 84th ceremony in 2023.
== Treatment == Gilbert's syndrome is a benign condition that typically requires no medical treatment. The primary approach involves patient education and reassurance about the harmless nature of the syndrome. Episodes of jaundice, when they occur, are usually mild and resolve on their own without intervention. To minimize the frequency of these episodes, individuals are advised to avoid known triggers such as fasting, dehydration, stress, and strenuous physical exertion. Maintaining a healthy lifestyle, including regular meals and adequate hydration, can help manage the condition effectively. If jaundice is significant, phenobarbital may be used.
Inorganic elements play critical roles in metabolism; some are abundant (e.g. sodium and potassium) while others function at minute concentrations. About 99% of a human's body weight is made up of the elements carbon, nitrogen, calcium, sodium, chlorine, potassium, hydrogen, phosphorus, oxygen and sulfur. Organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen; most of the oxygen and hydrogen is present as water. The abundant inorganic elements act as electrolytes. The most important ions are sodium, potassium, calcium, magnesium, chloride, phosphate and the organic ion bicarbonate. The maintenance of precise ion gradients across cell membranes maintains osmotic pressure and pH. Ions are also critical for nerve and muscle function, as action potentials in these tissues are produced by the exchange of electrolytes between the extracellular fluid and the cell's fluid, the cytosol. Electrolytes enter and leave cells through proteins in the cell membrane called ion channels. For example, muscle contraction depends upon the movement of calcium, sodium and potassium through ion channels in the cell membrane and T-tubules. Transition metals are usually present as trace elements in organisms, with zinc and iron being most abundant of those. Metal cofactors are bound tightly to specific sites in proteins; although enzyme cofactors can be modified during catalysis, they always return to their original state by the end of the reaction catalyzed.
Barbiturates can in most cases be used either as the free acid or as salts of sodium, calcium, potassium, magnesium, lithium, etc. Codeine- and dionine-based salts of barbituric acid have been developed.
Brentuximab vedotin, sold under the brand name Adcetris, is an antibody-drug conjugate medication used to treat relapsed or refractory Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (ALCL), a type of T cell non-Hodgkin lymphoma. It selectively targets tumor cells expressing the CD30 antigen, a defining marker of Hodgkin lymphoma and ALCL. The drug is being jointly marketed by Millennium Pharmaceuticals outside the US and by Seagen in the US.
Sources: en.wikipedia.org
These N-methyltryptamines are much more lipophilic than serotonin and, in contrast, are able to diffuse into serotonergic neurons and activate intracellular serotonin 5-HT2A receptors. Another metabolite of serotonin with possible psychedelic-like effects in animals is 5-methoxytryptamine (5-MT). DMT is a naturally occurring endogenous compound in the body. In relation to the fact that serotonin itself is unable to activate intracellular serotonin 5-HT2A receptors, it is possible that DMT might be the endogenous ligand of these receptors rather than serotonin.
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Each February, Tim Hortons holds a marketing campaign titled "Roll Up the Rim to Win". As of 2007, over 31 million prizes were distributed each year, including cars, televisions, and store products. Customers determine if they have won prizes by unrolling the rim on their paper cups when they have finished their drink, revealing the result underneath. Prizes are not distributed randomly country-wide; each of the company's distribution regions has distinct prize-winning odds. The idea for the campaign began in 1985 when Roger Wilson of one of Tim Hortons' supplier of cups, Lily Cup company, approached Tim Hortons with a new idea to increase their sales. Wilson explained his company had created a new cup design that allowed a message to be printed under the rim; the cup type cost no more than the current one and could enable a promotion or contest. Recognizing the opportunity to promote coffee in the normally weak sales period in the spring, the Roll Up the Rim to Win campaign was first held in 1986 when the biggest prize was a snack box of Timbits. In 2008, over 88% of major prizes were redeemed. The contest is popular enough that Paul Kind invented the Rimroller (as seen on Dragons' Den), a device for rolling up the rim mechanically. The contest has seen several controversies including the theft of unrolled cups. In March 2006, two families were fighting over a Toyota RAV4 SUV prize of CA$32,000 value when their daughters found a winning "roll up the rim" coffee cup in a garbage bin of an elementary school in Saint-Jérôme, Quebec.
India rejected Trump's offer to mediate India–China tensions. On February 13, 2025, Indian prime minister Narendra Modi became the fourth world leader to visit Donald Trump at the White House. In early 2025, deportations to Bhutan of Nepali-speaking Bhutanese refugees who had been settled in the US for nearly two decades resulted in statelessness of the deportees following their interrogation and expulsion from Bhutan upon arrival. Some of the refouled refugees, who had encountered largely minor legal issues in the US, were then arrested for illegal entry to Nepal upon seeking to re-enter the refugee camps they had previously inhabited before US resettlement.
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Sources: en.wikipedia.org
The mass difference from the linker is large enough for routine detection by mass spectrometry. The unconjugated form gives a single sharp signal at its expected weight. Material that has already reacted with albumin shows a much higher mass and a broadened chromatographic peak.
Yes. Degradation proceeds faster once the powder is dissolved, especially at room temperature or after multiple freeze and thaw cycles. Working solutions are often aliquoted to avoid repeated handling. Lyophilized powder held cold and dry retains its properties far longer.
Truncated sequences, oxidized residues and aggregated forms can all elute near the main peak. Reversed phase chromatography resolves many of these species, so the number of peaks is a useful indicator of synthesis quality. A single peak does not by itself prove correct sequence, which is why mass confirmation is paired with it.
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.