A practical reference on mass spectrometry: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-01-16. Anything still debated is marked as such rather than presented as settled.
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.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | Approximately 3.4 to 3.6 kDa | Depends on whether the affinity complex is attached |
| Appearance | White to off-white lyophilized powder | Freeze-dried solid, often in a sealed vial |
| Solubility | Soluble in water and aqueous buffers | Dissolution rate varies with pH and buffer salt |
| Typical storage | Below minus 20 degrees Celsius, dry and dark | Dissolved material is usually kept cold and used promptly |
| Common analytical methods | Reversed-phase HPLC and mass spectrometry | Peptide mapping and amino acid analysis add sequence detail |
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.
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.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
In March 1795, it was reported that the Suffolk had arrived in India after a four-month voyage without a trace of scurvy and with a crew that was healthier than when it set out. The effect was immediate. Fleet commanders clamored also to be supplied with lemon juice, and by June the Admiralty acknowledged the groundswell of demand in the navy and agreed to a proposal from the Sick and Hurt Board that lemon juice and sugar should in future be issued as a daily ration to the crews of all warships. It took a few years before the method of distribution to all ships in the fleet had been perfected and the supply of the huge quantities of lemon juice required to be secured, but by 1800, the system was in place and functioning. This led to a remarkable health improvement among the sailors and consequently played a critical role in gaining an advantage in naval battles against enemies who had yet to introduce the measures. Scurvy was not only a disease of seafarers. The early colonists of Australia suffered greatly because of the lack of fresh fruit and vegetables in the winter. There, the disease was called Spring fever or Spring disease and was described as an often-fatal condition associated with skin lesions, bleeding gums, and lethargy. It was eventually identified as scurvy and the remedies already in use at sea were implemented.
=== Invertebrate cartilage === Cartilage tissue can also be found among some arthropods such as horseshoe crabs, some mollusks such as marine snails and cephalopods, and some annelids like sabellid polychaetes.
=== 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.
Sources: en.wikipedia.org
E306 Tocopherol-rich extract (mixed, natural, can include tocotrienol) E307 Alpha-tocopherol (synthetic) E308 Gamma-tocopherol (synthetic) E309 Delta-tocopherol (synthetic) These E numbers include all racemic forms and acetate esters thereof. Commonly found on food labels in Europe and some other countries, their safety assessment and approval are the responsibility of the European Food Safety Authority.
For services to the community in Banbury, Oxfordshire. Malcolm John Kightley. For services to the Holy Sepulchre Church, Northampton. Lorna Jean King. For services to Jersey Hospice Care. Alison Kinnaird, Clarsach player and teacher, and glass engraver. For services to Music and to Art. Inna Kirillova. For services to Anglo/Russian relations. Captain Alex Kirk, lately Honorary Secretary, Hartlepool Lifeboat Station, Royal National Lifeboat Institution. For services to the RNLI. Bernadette Ann Kirk, Diabetes Specialist Nurse, Nottingham City Hospital NHS Trust. For services to Health Care. Donald Henry Kirk. For services to the Royal London Aid Society. Wendy Patricia Knight. For services to the British Red Cross Society in Hampshire. Alan Keith Knowles. For services to Remploy in Norwich, Norfolk. Mildred Eveline Knowles. For services to disabled people in Berkshire. Luis Eric Rupert de la Torre. For services to The St. Nazaire Society. Thomas Percival Langridge, Founder, the Pahar Trust. For charitable services. David Stuart Large, Constable, Cheshire Constabulary. For services to the Police and to the community in Winsford. Margaret Elsie Ann Lawrance. For services to the community in Loughton, Essex. Iain William Lawrence, Managing Director, Thomas Smith & Company (Peterhead) Ltd. For services to the Textile Industry. R. Mary Lawrence, Caretaker, Irfon Valley County Primary School, Powys. For services to Education and to the community. Bernard Robert Lawson, Lord Mayor's Secretary, Manchester City Council. For services to Local Government.
The fifth season had twelve roles receiving star billing, with eleven of them returning from the previous season, eight of which part of the original cast from the first season, and three new cast members being added. Kerry Washington continued to play her role as protagonist of the series, Olivia Pope, a former White House Director of Communications with her own crisis management firm. Darby Stanchfield played Abby Whelan, the White House Press Secretary, Katie Lowes portrayed Quinn Perkins, and Guillermo Diaz portrayed Huck, the troubled tech guy who works for Olivia. Cornelius Smith Jr. continued his role as activist Marcus Walker. after being upgraded to series regular. Jeff Perry continued to portray Cyrus Beene, chief of staff at the White House who was fired by Fitz but later rehired. Portia de Rossi played Elizabeth North, the new chief of staff at the White House, and later the chief of staff for the vice president. Joshua Malina played the role of David Rosen, former U.S. Attorney, now Attorney General. Bellamy Young continued to act as First Lady/Senator Melody "Mellie" Grant, who was kicked out of the White House by Fitz, and later joined the presidential campaign for president. Tony Goldwyn continued to portray President Fitzgerald "Fitz" Thomas Grant III. Scott Foley portrayed Jake Ballard a former B613 agent and later the head of the NSA. On May 14, 2015, after the fourth-season finale, it was announced that Portia de Rossi had been promoted to a series regular for the fifth season.
Archived from the original on January 11, 2013. "Paye ta plainte" [Pay for your complaint]. Le Groupe F (in French). Archived from the original on February 13, 2019. "Laboratoire de l'égalité" [Equality Lab] (in French). Archived from the original on January 18, 2019. "Paye ton taf" [Pay for your work] (in French). Archived from the original on April 13, 2019. "Délégation aux droits des femmes" [Delegation for Women's Rights]. Assemblée Nationale (in French). Archived from the original on June 24, 2020.
Sources: en.wikipedia.org
== Function and location == The OXTR protein belongs to the G protein-coupled receptor (GPCR) family, specifically Gq, and acts as a receptor for oxytocin. Its activity is mediated by G proteins that activate several different second messenger systems. Oxytocin receptors are expressed by the myoepithelial cells of the mammary gland, and in both the myometrium and endometrium of the uterus at the end of pregnancy. The oxytocin receptor system plays an important role as an inducer of uterine contractions during parturition and of milk ejection. OXTR is also associated with the central nervous system. The gene is believed to play a major role in social, cognitive, and emotional behavior. A decrease in OXTR expression by methylation of the OXTR gene is associated with callous and unemotional traits in adolescence, rigid thinking in anorexia nervosa, problems with facial and emotional recognition, and difficulties in the affect regulation. A reduction in this gene is believed to lead to prenatal stress, postnatal depression, and social anxiety. Studies on OXTR methylation—which downregulates oxytocin mechanisms—suggest this process is associated with increased gray matter density in the amygdala, implicating OXTR regulation in stress and parasympathetic regulation. Social isolation has been found to decrease oxytocin receptor levels in rodents, whereas levels of oxytocin were unchanged.
In some part of South China, soups (Chinese: 湯/汤 tāng) are served between the cold dishes and the main dishes. In other parts of China, soups are served between the main dish and staple foods, before desserts or fruit salad. There are many traditional Chinese soups, such as wonton soup, herbal chicken soup, hot and sour soup, winter melon soup, and so on.
February 15: Law on the repression of abortion, considered a crime against the interests of the state. August 6: Law amending article 344 of the Penal Code, concerning, among other things, inciting a minor to debauchery, as well as certain acts during consensual homosexual relations between a minor and an adult (but not in the case of similar acts within heterosexual relations). September 12: Law on women's work, again allowing the hiring of married women in the administration (suspending the previous law on the subject). September 22: Law on the effects of marriage regarding the rights and duties of spouses. December 16: Law on maternity and early childhood protection. December 23: Law aiming to "protect the dignity of the household from which the husband is absent due to wartime circumstances." 1943
Sources: en.wikipedia.org
The version carrying the affinity complex bears a maleimide group that binds serum albumin, which extends its circulation time to several days. The version without it lacks this group and clears within roughly half an hour. The two are chemically related but behave very differently once in the body.
In common usage the name without the affinity complex is often equated with MOD GRF 1-29, a fragment carrying four stabilizing substitutions. Strictly speaking, the term originally referred to the albumin-binding version. The overlap in naming causes frequent ambiguity in both informal and technical writing.
Reversed-phase chromatography separates the peptide from related impurities and yields a purity estimate. Mass spectrometry confirms the molecular mass and detects modifications such as oxidation. Sequence-level checks rely on peptide mapping or amino acid analysis when stronger confirmation is needed.
The two share the same 29-amino-acid backbone. CJC-1295 carries an additional albumin-binding moiety that markedly extends its residence time in circulation, while the form without that moiety clears faster. Literature sometimes applies the name loosely to either variant.