The short version of mass spectrometry fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-10 and is reviewed periodically as new material appears.
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.
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.
Lyophilised powder is the usual supplied form. The material is hygroscopic, so vials are typically equilibrated to room temperature before opening in order to prevent condensation on the contents. Long-term storage is generally described at minus twenty degrees Celsius or colder, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of soluble material. A reconstituted solution is considerably less stable than the dry powder and is normally kept refrigerated for short periods only.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography combined with mass spectrometry. The chromatographic separation resolves the target peptide from truncation products and from species carrying oxidised residues, while mass measurement confirms the expected molecular mass. Because the two common variants differ by roughly 280 daltons, a mass determination distinguishes them unambiguously. Purity is often quoted as a percentage of total peak area, although that figure depends on the detection wavelength and the integration method applied.
Reported half-lives differ widely between the two variants and between species. Values for the albumin-binding form are usually expressed in days, while the unconjugated form is measured in minutes to a few hours. Sampling schedules, assay sensitivity, and route of administration all influence the numbers, which limits direct comparison across studies. Whether sustained receptor occupancy produces different downstream effects from pulsatile stimulation remains an open question in the published work. Claims about relative potency should therefore be read alongside the specific study design that produced them.
| Property | Value | Notes |
|---|---|---|
| Peptide class | Synthetic GHRH analogue | Built on a 29 residue sequence |
| Primary target | GHRH receptor (GHRHR) | Class B G protein coupled receptor |
| Unconjugated half life | Minutes | Limited by protease degradation |
| Key modification | Four residue substitutions | Positions 2, 8, 15 and 27 |
| Common synonym | Modified GRF(1-29) | Usually denotes the form without DAC |
Once the immunoliposomes deliver the appropriate drugs to the targeted cells, they can enter the cell using either selective uptake of liposomes by endocytosis or liposome release near the targeted cell. Because of antibody conjunction, the cellular uptake amount is increased for immunoliposomes allowing greater drug entry into diseased cells. To control when a drug is released, immunoliposomes are being developed that can sense stimuli. This stimuli can come from the microenvironment of a tumor using factors such as reduced pH, temperature, and enzyme levels. External stimuli like light, heat, magnetic fields, or ultrasound can also act as a trigger for drug release. Immunoliposomes can target a wide variety of cell options. This can be split into two main types commonly known as intravascular and extravascular space as seen in Figure 4. Intravascular cells are more accessible during circulation and include erythrocytes, myeloid cells, lymphocytes, neutrophils, etc. Extravascular cells are located on tissue parenchymal or stromal cells. Because immunoliposomes have many antibody copies, they contain a higher avidity than just one antibody alone allowing for effective targeting against cancer cells and some drug resistant cells.
==== 2000s ==== 2000 – First Medical Inc., Amelung GmbH, ARK Scientific 2001 – ISOTEC (produces stable isotopes used in basic research and medical diagnostics) 2004 – Ultrafine (a supplier of contract manufacturing services for drug development), Tetrionics (a producer of high potency and cytotoxic active pharmaceutical ingredients) 2005 – JRH Biosciences, an industrial supplier of cell culture products for the pharmaceutical and biotechnology industries; Proligo Group, a global supplier of genomics research tools 2006 – Beijing Superior Chemicals, Iropharm, Pharmorphix, Advanced Separation Technologies (manufacturer of products for chiral chromatography) 2007 – Epichem acquired to expand capabilities in materials sciences and semiconductor markets; Molecular Medicine BioServices acquired to provide large-scale viral manufacturing capabilities; announced alliance with Sangamo BioSciences to develop zinc finger-based laboratory research reagents 2009 – ChemNavigator 2010 – Cerilliant Corporation, ACE Animals 2011 – Resource Technology Corp, Vetec Quimica Fina 2012 – Research Organics Inc., BioReliance (a toxicology and veterinary diagnostics company); BioReliance had previously been acquired by Invitrogen and subsequently sold to Avista Capital Partners. 2014 – Cell Marque 2015 – Combined with EMD Millipore to make MilliporeSigma.
== Gene == In humans, COL21A1 is located on the short arm of chromosome 6 at band 6p12.3–p11.2. The gene spans approximately 337 kb of genomic DNA and contains 31 exons; its 5′-untranslated exons (exon 1 and exon 1a) are alternatively spliced, and alternative splicing of the gene gives rise to multiple transcript variants. The exon–domain organization of COL21A1 resembles that of other genes encoding FACIT collagens.
Sources: en.wikipedia.org
=== Pantoprazole === The story of pantoprazole's discovery is a good example of the stepwise development of PPIs. The main focus of modification of timoprazole was the benzimidazole part of its structure. Addition of a trifluoromethyl group to the benzimidazole moiety led to a series of very active compounds with varying solution-stability. In general fluoro substituents were found to block metabolism at the point where they were attached. Later the more balanced fluoroalkoxy substituent, instead of the highly lipophilic and strongly electron-withdrawing trifluoromethyl substituent, led to highly active compounds with supposed longer half-lives and higher solution stability. It was realized that activity was somehow linked to instability in solution and then came to the conclusion that the cyclic sulfenamides, formed in acidic conditions, were the active principle of the PPIs. Finally, it was understood that seemingly small alterations in the backbone of timoprazole led nowhere, and focus had to be centered on the substituents on the backbone. However, necessary intramolecular rearrangement of the benzimidazole into sulfenamide posed severe geometric constraints. Optimal compounds would be those that were stable at neutral pH but were quickly activated at low pH. A clear-cut design of active inhibitors was still not possible because in the complex multi-step chemistry the influence of a substituent on each step in the cascade could be different, and therefore not predictable for the overall rate of the prerequisite acid activation.
A pi helix (or π-helix) is a type of secondary structure found in proteins. Discovered by crystallographer Barbara Low in 1952 and once thought to be rare, short π-helices are found in 15% of known protein structures and are believed to be an evolutionary adaptation derived by the insertion of a single amino acid into an α-helix. Because such insertions are highly destabilizing, the formation of π-helices would tend to be selected against unless it provided some functional advantage to the protein. π-helices therefore are typically found near functional sites of proteins.
The pitot tube and static port on an aircraft are used to determine the airspeed of the aircraft. These two devices are connected to the airspeed indicator, which determines the dynamic pressure of the airflow past the aircraft. Bernoulli's principle is used to calibrate the airspeed indicator so that it displays the indicated airspeed appropriate to the dynamic pressure. A De Laval nozzle utilizes Bernoulli's principle to create a force by turning pressure energy generated by the combustion of propellants into velocity. This then generates thrust by way of Newton's third law of motion. The flow speed of a fluid can be measured using a device such as a Venturi meter or an orifice plate, which can be placed into a pipeline to reduce the diameter of the flow. For a horizontal device, the continuity equation shows that for an incompressible fluid, the reduction in diameter will cause an increase in the fluid flow speed. Subsequently, Bernoulli's principle then shows that there must be a decrease in the pressure in the reduced diameter region. This phenomenon is known as the Venturi effect. The maximum possible drain rate for a tank with a hole or tap at the base can be calculated directly from Bernoulli's equation and is found to be proportional to the square root of the height of the fluid in the tank. This is Torricelli's law, which is compatible with Bernoulli's principle. Increased viscosity lowers this drain rate; this is reflected in the discharge coefficient, which is a function of the Reynolds number and the shape of the orifice.
Sources: en.wikipedia.org
== History == Prosenjit Choudhury was, at the time, a culinary expert at Sayaji Hotels. While working at the hotel, he introduced the concept of live grills similar to Korean barbecue in order to enhance the buffet experience to avoid cold appetisers. This idea proved to be popular and with the support of Sajid Dhanani, the managing director of Sayaji Hotels, Choudhury established the first outlet at Pali Hill in Mumbai, India in 2006. The brand had expanded to cities such as New Delhi and Bengaluru by 2008. After Sajid Dhanani's death in 2012, his brother Kayum Dhanani took over the business. The company opened its 100th outlet in 2018. The company offered its IPO in 2021. The IPO raised ₹453 crore (US$52 million), with ₹180 crore as fresh capital for expansion and debt repayment, and ₹273 crore as an offer for sale by existing investors. The stock was reported to perform poorly, due to factors such as the COVID-19 pandemic's impact on the restaurant market, weakening sales and increased competition. An Indian Express article highlighted how the buffet business was stalling due to new customer trends, affecting the growth of Barbeque Nation. As of 2022, the company owns an 86.57% stake in Red Apple Kitchen Consultancy Private Limited, which manages an Italian restaurant chain, Toscano.
== Specials == 空山鳥語 - kōngshān niǎo yǔ - Birdsong in Hollow Valley 2014 This special consists of three episodes which tells the story of Baifeng and his friend Moya who were assassins for General Ji Wuye, but who turn against him after Baifeng falls for a female assassin, Nong Yu.
=== Cellular evaluation === Full blood count – Routine laboratory test of blood cellsPages displaying short descriptions of redirect targets Hematocrit – Volume percentage of red blood cells in blood Mean corpuscular volume (MCV) – Average volume of a red blood cell, which sometimes helps in diagnosis Mean corpuscular hemoglobin concentration (MCHC) – Measure of hemoglobin concentration in red blood cells Erythrocyte sedimentation rate (ESR) – Physiological quantity Cross-matching. Determination of blood type for blood transfusion or transplants Blood cultures are commonly taken if infection is suspected. Positive cultures and resulting sensitivity results are often useful in guiding medical treatment.
Sources: en.wikipedia.org
The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.
DAC stands for drug affinity complex, a term describing the maleimidopropionic acid linker. This group forms a covalent bond with the cysteine residue on serum albumin after administration. The resulting adduct is what extends the circulating half life from minutes to days.
No. It is entirely synthetic and does not correspond to any known endogenous peptide. The design starts from human growth hormone releasing hormone and introduces deliberate substitutions. Any biological effect comes from mimicking the natural hormone at its receptor.
Chromatography reports how much material elutes as a single peak but does not confirm what that material is. Mass spectrometry supplies the molecular mass, which is characteristic of a given sequence and its modifications. Together the two methods support both a purity figure and an identity claim.