The short version of reversed-phase HPLC fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
| 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 |
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
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.
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.
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.
Non-lamellar phases are known as non-bilayer liquid-crystalline phases without lamellar symmetry (Lα). They include hexagonal (I), hexagonal (II), and three-dimensional cubic phases. Hexagonal (I) phases are non-inverted or oil-in-water phases in which a net convex curvature is present and this is similar to micelles. Hexagonal(II) phases are inverted water-in-oil phases with net concave curvatures describing the lipid and water interactions. Cubic phases (Pn3m, Im3m, la3d, etc.) or bicontinuous cubic phases composed of multiple connected bilayers that resemble a three-dimensional cube. The presence of non-lamellar lipids in biomembranes affect the elasticity of the lipid bilayer, especially when it is disrupted, for example during phase transitions, membrane fusion and fission or interactions with membrane peptides and proteins.
No more extortions, no more killings of innocent people! Zetas in the state of Veracruz and politicians helping them: This is going to happen to you, or we can shoot you as we did to you guys before too. People of Veracruz, do not allow yourselves to be extorted; do not pay for protection; if you do is because you want to. This is the only thing these people (Los Zetas) can do. This is going to happen to all the Zeta-shits who continue to operate in Veracruz. This territory has a new proprietor. The Blog del Narco reported on 21 September 2011 that the message was supposedly signed by Gente Nueva, an enforcer group that works for Joaquín Guzmán Loera, the top boss of the Sinaloa cartel. Nonetheless, on 27 September 2011, the CJNG released a video claiming they had carried out these attacks. They apologized for the massacres in Veracruz but reiterated their efforts to fight off Los Zetas, who, they claimed, "are not invincible." In the CJNG video, five men wearing balaclavas and completely black clothing are shown sitting behind a table. Then the man with the microphone states that the Matazetas are "warriors without a face, but proudly Mexicans", and that their objective is to eradicate Los Zetas. They claim in the video that they respect the Mexican Armed Forces and understand the government's stance against the drug cartels. The men in the video state that they understand and respect the government's decision of refusing to negotiate with the cartels. They also criticize the politicians who have protected Los Zetas.
=== Oxidation === Plasma processing, corona treatment, and flame treatment can all be classified as surface oxidation mechanisms. These methods all involve cleavage of polymer chains in the material and the incorporation of carbonyl, and hydroxyl functional groups. The incorporation of oxygen into the surface creates a higher surface energy allowing the substrate to be coated.
Sources: en.wikipedia.org
It performs antimicrobial functions in microorganisms like algae, fungi, bacteria, and gram-positive bacteria of different yeast species. Chitosan composite for tissue engineering: Chitosan powder blended with alginate is used to form functional wound dressings. These dressings create a moist, biocompatible environment which aids in the healing process. This wound dressing is also biodegradable and has porous structures that allows cells to grow into the dressing. Furthermore, thiolated chitosans (see thiomers) are used for tissue engineering and wound healing, as these biopolymers are able to crosslink via disulfide bonds forming stable three-dimensional networks.
=== Applications and operating systems === 1979: Apple II: VisiCalc (first spreadsheet program and killer app) 1979: CP/M systems: WordStar 1982: WordStar ported to CP/M-86 and IBM PC compatible/MS-DOS 1983: IBM PC compatible/MS-DOS: Lotus 1-2-3 (spreadsheet) 1985: Macintosh: Microsoft Excel (first WYSIWYG spreadsheet) and Microsoft Word (WYSIWYG word processor), Aldus (now Adobe) PageMaker (first desktop publishing program) 1985: AmigaOS: Deluxe Paint, Video Toaster, Prevue Guide 1987/1989: Microsoft Excel and Microsoft Word ported to Microsoft Windows 1993: Acorn Archimedes: Sibelius
== Applications == Freeze-drying causes less damage to the substance than other dehydration methods using higher temperatures. Nutrient factors that are sensitive to heat are lost less in the process as compared to the processes incorporating heat treatment for drying purposes. Freeze-drying does not usually cause shrinkage or toughening of the material being dried. In addition, flavors, smells, and nutritional content generally remain unchanged, making the process popular for preserving food. However, water is not the only chemical capable of sublimation, and the loss of other volatile compounds such as acetic acid (vinegar) and alcohols can yield undesirable results. Freeze-dried products can be rehydrated (reconstituted) much more quickly and easily because the process leaves microscopic pores. The pores are created by the ice crystals that sublimate, leaving gaps or pores in their place. This is especially important when it comes to pharmaceutical uses. Freeze-drying can also be used to increase the shelf life of some pharmaceuticals for many years.
=== Safety === As for safety, the IOM sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of pantothenic acid, there is no UL, as there is no human data for adverse effects from high doses. The EFSA also reviewed the safety question and reached the same conclusion as in the United States – that there was not sufficient evidence to set a UL for pantothenic acid.
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.