Reversed-phase HPLC raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-08-11. Anything still debated is marked as such rather than presented as settled.
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.
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
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.
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.
Peptide degradation proceeds mainly through hydrolysis, oxidation of methionine, and deamidation of asparagine or glutamine residues. The maleimide group on the albumin-binding variant can also react with thiols or hydrolyze in aqueous media. Because these pathways accelerate with temperature and pH extremes, handling conditions strongly influence measured stability. Stability data in the public literature are limited and often generated under differing conditions, so general statements about shelf life should be read as approximate.
Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.
This was subsequently transferred to Innate Pharma in March 2020. On 10 December 2020, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization under exceptional circumstances for the medicinal product Lumoxiti, intended for the treatment of relapsed or refractory hairy cell leukemia after two prior systemic therapies including a purine nucleoside analog. The orphan designation for Lumoxiti for treatment of hairy cell leukaemia was also maintained. The applicant for this medicinal product is AstraZeneca AB. Moxetumomab pasudotox was approved for medical use in the European Union in February 2021. The EU marketing authorization was withdrawn in July 2021.
=== Debate over origins === Murdijati Gardjito, a food historian at Gadjah Mada University, argued that tempeh was made by native Javanese people and that its preparation predates the introduction of Chinese-style tofu products. Some ancient texts mention tempe dhele, old Javanese for 'native soybean tempeh'; dhele was used to refer to the native soybean variety. White soybeans that are used to make most tempe dhele today used to be called dhele putih ('white soybeans'), and were only available in Java centuries later. Mary Astuti, a food historian at Gadjah Mada University specializing in tempeh, argued that the native variety of soybean had been grown before the Chinese arrived in the region. Sri Tandjung noted that Javanese had been eating cooked (native black) soybeans since the 12th century. By the 16th or the 19th century, depending on which period of time the writer of Serat Centhini referred to, Javanese people had mastered the art of cooking with tempeh, when it was not only eaten as is, but converted into different types of dishes, showing a full understanding and mastery of the food product. Gardjito noted that Javanese noble families rarely wrote about tempeh in ancient texts because it had never been a part of royal cuisine, but rather a staple food of the lower classes. Indonesian historian Ong Hok Ham suggests that tempeh might have been produced as a byproduct of tahu, the Indonesian word for tofu.
=== EC 2.7.7: Nucleotidyltransferases === EC 2.7.7.1: nicotinamide-nucleotide adenylyltransferase EC 2.7.7.2: FAD synthase EC 2.7.7.3: pantetheine-phosphate adenylyltransferase EC 2.7.7.4: sulfate adenylyltransferase EC 2.7.7.5: sulfate adenylyltransferase (ADP) EC 2.7.7.6: DNA-directed RNA polymerase EC 2.7.7.7: DNA-directed DNA polymerase EC 2.7.7.8: polyribonucleotide nucleotidyltransferase EC 2.7.7.9: UTP—glucose-1-phosphate uridylyltransferase EC 2.7.7.10: UTP—hexose-1-phosphate uridylyltransferase EC 2.7.7.11: UTP—xylose-1-phosphate uridylyltransferase EC 2.7.7.12: UDP-glucose—hexose-1-phosphate uridylyltransferase EC 2.7.7.13: mannose-1-phosphate guanylyltransferase EC 2.7.7.14: ethanolamine-phosphate cytidylyltransferase EC 2.7.7.15: choline-phosphate cytidylyltransferase EC 2.7.7.16: Now EC 4.6.1.18, pancreatic ribonuclease EC 2.7.7.17: Now EC 4.6.1.19, ribonuclease T2 EC 2.7.7.18: nicotinate-nucleotide adenylyltransferase EC 2.7.7.19: polynucleotide adenylyltransferase EC 2.7.7.20: deleted (identical with EC 2.7.7.72, CCA tRNA nucleotidyltransferase EC 2.7.7.21: Now EC 2.7.7.72, CCA tRNA nucleotidyltransferase EC 2.7.7.22: mannose-1-phosphate guanylyltransferase (GDP) EC 2.7.7.23: UDP-N-acetylglucosamine diphosphorylase EC 2.7.7.24: glucose-1-phosphate thymidylyltransferase EC 2.7.7.25: Now EC 2.7.7.72, CCA tRNA nucleotidyltransferase EC 2.7.7.26: Now EC 4.6.1.24, ribonuclease T1 EC 2.7.7.27: glucose-1-phosphate adenylyltransferase EC 2.7.7.28: nucleoside-triphosphate-hexose-1-phosphate nucleotidyltransferase EC 2.7.7.29: identical to EC 2.7.7.28, nucleoside-triphosphate-hexose-1-phosphate nucleotidyltransferase EC 2.7.7.30: fucose-1-phosphate guanylyltransferase EC 2.7.7.31: DNA nucleotidylexotransferase EC 2.7.7.32: galactose-1-phosphate thymidylyltransferase EC 2.7.7.33: glucose-1-phosphate cytidylyltransferase EC 2.7.7.34: glucose-1-phosphate guanylyltransferase EC 2.7.7.35: ribose-5-phosphate adenylyltransferase EC 2.7.7.36: aldose-1-phosphate adenylyltransferase EC 2.7.7.37: aldose-1-phosphate nucleotidyltransferase EC 2.7.7.38: 3-deoxy-manno-octulosonate cytidylyltransferase EC 2.7.7.39: glycerol-3-phosphate cytidylyltransferase EC 2.7.7.40: D-ribitol-5-phosphate cytidylyltransferase EC 2.7.7.41: phosphatidate cytidylyltransferase EC 2.7.7.42: [glutamine synthetase] adenylyltransferase EC 2.7.7.43: N-acylneuraminate cytidylyltransferase EC 2.7.7.44: glucuronate-1-phosphate uridylyltransferase EC 2.7.7.45: guanosine-triphosphate guanylyltransferase EC 2.7.7.46: gentamicin 2′′-nucleotidyltransferase EC 2.7.7.47: streptomycin 3′′-adenylyltransferase EC 2.7.7.48: RNA-directed RNA polymerase EC 2.7.7.49: RNA-directed DNA polymerase EC 2.7.7.50: mRNA guanylyltransferase EC 2.7.7.51: adenylylsulfate—ammonia adenylyltransferase EC 2.7.7.52: RNA uridylyltransferase EC 2.7.7.53: ATP adenylyltransferase EC 2.7.7.54: The activity is part of EC 6.3.2.40, cyclopeptine synthase EC 2.7.7.55: The activity is part of EC 6.3.2.40, cyclopeptine synthase EC 2.7.7.56: tRNA nucleotidyltransferase EC 2.7.7.57: N-methylphosphoethanolamine cytidylyltransferase EC 2.7.7.58: Now included in EC 6.2.1.71, 2,3-dihydroxybenzoate[aryl-carrier protein] ligase EC 2.7.7.59: [protein-PII] uridylyltransferase EC 2.7.7.60: 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase EC 2.7.7.61: citrate lyase holo-[acyl-carrier protein] synthase EC 2.7.7.62: adenosylcobinamide-phosphate guanylyltransferase EC 2.7.7.63: Now EC 6.3.1.20, lipoate—protein ligase EC 2.7.7.64: UTP-monosaccharide-1-phosphate uridylyltransferase EC 2.7.7.65: diguanylate cyclase EC 2.7.7.66: malonate decarboxylase holo-[acyl-carrier protein] synthase EC 2.7.7.67: CDP-2,3-bis-(O-geranylgeranyl)-sn-glycerol synthase EC 2.7.7.68: 2-phospho-L-lactate guanylyltransferase EC 2.7.7.69: GDP-L-galactose/GDP-D-glucose: hexose 1-phosphate guanylyltransferase EC 2.7.7.70: D-glycero-β-D-manno-heptose 1-phosphate adenylyltransferase EC 2.7.7.71: D-glycero-α-D-manno-heptose 1-phosphate guanylyltransferase EC 2.7.7.72: CCA tRNA nucleotidyltransferase EC 2.7.7.73: sulfur carrier protein ThiS adenylyltransferase EC 2.7.7.74: 1L-myo-inositol 1-phosphate cytidylyltransferase EC 2.7.7.75: molybdopterin adenylyltransferase EC 2.7.7.76: molybdenum cofactor cytidylyltransferase EC 2.7.7.77: molybdenum cofactor guanylyltransferase EC 2.7.7.78: GDP-D-glucose phosphorylase EC 2.7.7.79: tRNAHis guanylyltransferase EC 2.7.7.80: molybdopterin-synthase adenylyltransferase EC 2.7.7.81: pseudaminic acid cytidylyltransferase EC 2.7.7.82: CMP-N,N′-diacetyllegionaminic acid synthase EC 2.7.7.83: UDP-N-acetylgalactosamine diphosphorylase EC 2.7.7.84: diadenylate cyclase EC 2.7.7.85: 2′-5′ oligoadenylate synthase EC 2.7.7.86: cyclic GMP-AMP synthase EC 2.7.7.87: L-threonylcarbamoyladenylate synthase EC 2.7.7.88: GDP polyribonucleotidyltransferase EC 2.7.7.89: [glutamine synthetase]-adenylyl-L-tyrosine phosphorylase EC 2.7.7.90: 8-amino-3,8-dideoxy-''manno''-octulosonate cytidylyltransferase EC 2.7.7.91: valienol-1-phosphate guanylyltransferase EC 2.7.7.92: 3-deoxy-D-glycero-D-galacto-nonulopyranosonate cytidylyltransferase EC 2.7.7.93: phosphonoformate cytidylyltransferase EC 2.7.7.94: Now EC 6.2.1.51, 4-hydroxyphenylalkanoate adenylyltransferase FadD29 EC 2.7.7.95: Now EC 6.2.1.49, long-chain fatty acid adenylyltransferase FadD28 EC 2.7.7.96: ADP-D-ribose pyrophosphorylase EC 2.7.7.97: 3-hydroxy-4-methylanthranilate adenylyltransferase EC 2.7.7.98: Now EC 6.2.1.50, 4-hydroxybenzoate adenylyltransferase FadD22 EC 2.7.7.99: N-acetyl-α-D-muramate 1-phosphate uridylyltransferase EC 2.7.7.100: SAMP-activating enzyme EC 2.7.7.101: DNA primase DnaG EC 2.7.7.102: DNA primase AEP EC 2.7.7.103: L-glutamine-phosphate cytidylyltransferase EC 2.7.7.104: 2-hydroxyethylphosphonate cytidylyltransferase EC 2.7.7.105: phospho''enol''pyruvate guanylyltransferase EC 2.7.7.106: 3-phospho-D-glycerate guanylyltransferase
Sources: en.wikipedia.org
=== Behavioral evidence === Fossils of the troodonts Mei and Sinornithoides demonstrate that some dinosaurs slept with their heads tucked under their arms. This behavior, which may have helped to keep the head warm, is also characteristic of modern birds. Several deinonychosaur and oviraptorosaur specimens have also been found preserved on top of their nests, likely brooding in a bird-like manner. The ratio between egg volume and body mass of adults among these dinosaurs suggest that the eggs were primarily brooded by the male and that the young were highly precocial, similar to many modern ground-dwelling birds. Some dinosaurs are known to have used gizzard stones like modern birds. These stones are swallowed by animals to aid digestion and break down food and hard fibers once they enter the stomach. When found in association with fossils, gizzard stones are called gastroliths.
==== India ==== The Department of Information Technology created the Indian Computer Emergency Response Team (CERT-In) in 2004 to thwart cyber attacks in India. That year, there were 23 reported cyber security breaches. In 2011, there were 13,301. That year, the government created a new subdivision, the National Critical Information Infrastructure Protection Centre (NCIIPC) to thwart attacks against energy, transport, banking, telecom, defense, space and other sensitive areas. The executive director of the Nuclear Power Corporation of India (NPCIL) stated in February 2013 that his company alone was forced to block up to ten targeted attacks a day. CERT-In was left to protect less critical sectors. A high-profile cyber attack on 12 July 2012 breached the email accounts of about 12,000 people, including those of officials from the Ministry of External Affairs, Ministry of Home Affairs, Defense Research and Development Organizations (DRDO), and the Indo-Tibetan Border Police (ITBP). A government-private sector plan being overseen by National Security Advisor (NSA) Shivshankar Menon began in October 2012, and intends to boost up India's cyber security capabilities in the light of a group of experts findings that India faces a 470,000 shortfall of such experts despite the country's reputation of being an IT and software powerhouse. In February 2013, Information Technology Secretary J. Satyanarayana stated that the NCIIPC was finalizing policies related to national cyber security that would focus on domestic security solutions, reducing exposure through foreign technology.
Indoors ozone (O3) is produced by certain high-voltage electric devices (such as air ionizers), and as a by-product of other types of pollution. It appears in lower concentrations indoors than outdoors, usually at 0.2–0.7 of the outdoor concentration. Typically, most ozone is lost to surface reactions indoors, rather than to reactions in air, due to the large surface to volume ratios found indoors. Outdoor air used for ventilation may have sufficient ozone to react with common indoor pollutants as well as skin oils and other common indoor air chemicals or surfaces. Particular concern is warranted when using "green" cleaning products based on citrus or terpene extracts, because these chemicals react rapidly with ozone to form toxic and irritating chemicals as well as fine and ultrafine particles. Ventilation with outdoor air containing elevated ozone concentrations may complicate remediation attempts. The WHO standard for ozone concentration is 60 μg/m3 for long-term exposure and 100 μg/m3 as the maximum average over an 8-hour period. The EPA standard for ozone concentration is 0.07 ppm average over an 8-hour period.
=== Chemical industry === Stainless-steel belts are part of continuous production processes. Unlike conveyor belts used purely for transportation purposes, steel belts used in this industry serve as media for transferring heat and/or pressure. Applications for steel belts in the chemical industry include casting, polymerizing of resins, waxes, paraffins and many other substances.
Sources: en.wikipedia.org
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.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.