freeze-drying 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.
Updated 2026-06-04. Numbers and descriptions here follow the published literature rather than marketing material.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
2023 Christie G. Enke and Richard Yost for their development of the triple quadrupole mass spectrometer and the tremendous impact triple quads have made for a wide range of biomedical research applications. 2022 Jennifer Lippincott-Schwartz 2020 George Church for his groundbreaking research in genomic sequencing and his leadership in the fields of gene therapy and synthetic biology technologies. 2019 Richard M. Caprioli for the discovery of temporal and spatial processing in biological systems using mass spectrometry. 2018 Amos Bairoch for the development of community resources such as UniProtKB/Swiss-Prot knowledgebase, PROSITE, ENZYME, and neXtProt. 2017 Sir Shankar Balasubramanian and David Klenerman for the invention of a method of next-generation DNA sequencing which is commonly known today as "sequencing by synthesis". 2016 Emmanuelle Charpentier and Jennifer Doudna for the development of CRISPR/Cas9 Genome Editing Technologies. 2015 John G. White and William Bradshaw Amos for the development of high-resolution, laser scanning confocal microscope 2014 Patrick H. O'Farrell, for the development of 2-dimensional gel electrophoresis. 2013 Leonard Herzenberg and Leonore Herzenberg for the development of Flow Activated Cell Sorting (FACS). 2012 Alan G. Marshall for the development of Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry.
==== Bone and collagen ==== Cortisol reduces bone formation, favoring long-term development of osteoporosis (progressive bone disease). The mechanism behind this is two-fold: cortisol stimulates the production of RANKL by osteoblasts which stimulates, through binding to RANK receptors, the activity of osteoclasts, cells responsible for calcium resorption from bone, and also inhibits the production of osteoprotegerin (OPG) which acts as a decoy receptor and captures some RANKL before it can activate the osteoclasts through RANK. In other words, when RANKL binds to OPG, no response occurs as opposed to the binding to RANK which leads to the activation of osteoclasts. It transports potassium out of cells in exchange for an equal number of sodium ions (see above). This can trigger the hyperkalemia of metabolic shock from surgery. Cortisol also reduces calcium absorption in the intestine. Cortisol down-regulates the synthesis of collagen.
=== Veterinary use === An SSRI (fluoxetine) has been approved for veterinary use in treatment of canine separation anxiety. Like in human medicine, fluoxetine is extensively used off-label in animal medicine. In dogs and cats, it is mainly prescribed off-label for behavior problems.
== Medical uses == Datopotamab deruxtecan is indicated for the treatment of adults with unresectable or metastatic, hormone receptor positive, human epidermal growth factor receptor 2-negative (IHC 0, IHC1+ or IHC2+/ISH-) breast cancer who have received prior endocrine-based therapy and chemotherapy for unresectable or metastatic disease. In June 2025, the US Food and Drug Administration (FDA) expanded the indication to include the treatment of adults with locally advanced or metastatic epidermal growth factor receptor-mutated non-small cell lung cancer who have received prior epidermal growth factor receptor-directed therapy and platinum-based chemotherapy. In May 2026, the FDA expanded the indication to include the treatment of adults with unresectable or metastatic triple-negative breast cancer who are not candidates for PD-1/PD-L1 inhibitor therapy.
Sources: en.wikipedia.org
Tellurium readily alloys with iron, as ferrotellurium (50–58% tellurium), and with copper, in the form of tellurium copper (40–50% tellurium). Ferrotellurium is used as a stabilizer for carbon in steel casting. Of the non-metallic elements less often recognised as metalloids, selenium – in the form of ferroselenium (50–58% selenium) – is used to improve the machinability of stainless steels.
== Cultivation == Peppermint generally grows best in moist, shaded locations, and expands by underground rhizomes. Young shoots are taken from old stocks and dibbled into the ground about 0.5 m (1.5 ft) apart. They grow quickly and cover the ground with runners if it is permanently moist. For the home gardener, it is often grown in containers to restrict rapid spreading. It grows best with a good supply of water, without being waterlogged, and planted in areas with partial sun to shade. The leaves and flowering tops are used; they are collected as soon as the flowers begin to open and can be dried. The wild form of the plant is less suitable for this purpose, with cultivated plants having been selected for more and better oil content. They may be allowed to lie and wilt a little before distillation, or they may be taken directly to the still.
==== Types of diabetes mellitus ==== Between 1850 and 1875, French researchers Apollinaire Bouchardat and E. Lancereux acknowledged a need for classification. They distinguished between those diabetics that were lean, had severe symptoms, poor outcomes, and pancreatic lesions at autopsy (diabetes maigre), and those that were overweight, presented later in life with a milder form of the disease and had a better prognosis if put on a low-calorie diet (diabetes gras). These descriptions are comparable to the two types identified by Ayurvedic physicians Sushruta and Charaka (400–500 AD), with one type being associated with youth and the other with being overweight. Harold Percival Himsworth established a clearer distinction in 1936, differentiating two types of diabetes based on sensitivity to insulin (both injected and pancreatic). In 1950, R. D. Lawrence observed that some diabetics were deficient in insulin and that some were not. Philip Hugh-Jones, while working in Jamaica in 1955, clarified Lawrence's classification and coined the terms "type 1" and "type 2" diabetes. He also noted a rarer variety observed in insulin-resistant youth (whose condition could not be placed into the two types). He called this third group "type J", where J stood for Jamaica. The terms type 1 and 2 were for some time forgotten. In 1976, they were revived and popularized by Andrew Cudworth after he discovered the link between type 1 diabetes and a specific genetic marker.
== B == B-cell lymphoma – B cells – B lymphocytes (B cells) – bactericidal – bacteriostatic – bacterium – baculovirus – baseline – basophil – bDNA test – beta-2 microglobulin (β2M) – bilirubin – bioavailability – biological response modifiers (BRMs) – biopsy – biotechnology – blinded study – blips – blood–brain barrier – body fat redistribution (BFR) syndrome – body fluids – bone marrow – bone marrow suppression – booster – branched DNA assay – breakthrough infection – Broadway Cares/Equity Fights AIDS – bronchoscopy – budding – buffalo hump – bugchasing and giftgiving – Burkitt's lymphoma
== Available forms == A branded version of the drug is owned by Astellas Pharma, and is sold under the brand name Prograf, given twice daily. A number of other manufacturers hold marketing authorisation for alternative brands of the twice-daily formulation. Once-daily formulations with marketing authorisation include Advagraf (Astellas Pharma) and Envarsus (marketed as Envarsus XR in US by Veloxis Pharmaceuticals and marketed in Europe by Chiesi). These formulations are intended to reduce pharmacokinetic variation in blood levels and facilitate compliance with dosing. The topical formulation is marketed by LEO Pharma under the name Protopic.
Sources: en.wikipedia.org
June 4: Tiananmen Square Massacre: Beijing protests are crushed by the communist Chinese government, resulting in an unknown number of deaths. June 4: Elections in Poland show complete lack of backing for the Communist Party; Solidarity trade union wins all available seats in the Parliament and 99% in the Senate. August 19: The opening of the border gate between Austria and Hungary at the Pan-European Picnic set in motion a chain reaction, at the end of which there was no longer a GDR and the Eastern Bloc had disintegrated. August 23: Baltic Way: independence protesters in Estonia, Latvia and Lithuania set up a human chain across the three Baltic states, from Tallinn to Vilnius via Riga. August: Parliament in Poland elects Tadeusz Mazowiecki as leader of the first non-communist government in the Eastern Bloc. October 7: Hungarian Socialist Workers' Party, the ruling party of Hungary, is dissolved. October 18: The Hungarian constitution is amended to allow a multi-party political system and elections. In East Germany, the nearly 20-year term of communist leader Erich Honecker comes to an end. November 7: Civil unrest occurred in Moldova. November 9: Revolutions of 1989: Soviet reforms have allowed Eastern Europe to change the Communist governments there. The Berlin Wall is breached when Politburo spokesman, Günter Schabowski, not fully informed of the technicalities or procedures of the newly agreed lifting of travel restrictions, mistakenly announces at a news conference in East Berlin that the borders have been opened.
=== Dental implants === The most common use of bone grafting is in the application of dental implants to restore the edentulous area of a missing tooth. Dental implants require bones underneath them for support and proper integration into the mouth. As mentioned earlier bone grafts come in various forms such as autologous (from the same person), Allograft, Xenograft (mainly bovine bone), and Alloplastic materials. Bone grafts can be used prior to implant placement or simultaneously. People who have been edentulous (without teeth) for a prolonged period may not have enough bone left in the necessary locations. In this case, autologous bone can be taken from the chin, from the pilot holes for the implants, or even from the iliac crest of the pelvis and inserted into the mouth underneath the new implant. Alternatively, exogenous bone can be used: xenograft is the most commonly used, because it offers the advantage of exceptional volume stability over time. Allograft offers the best regeneration quality but has lower volume stability. Often a mix of different kinds of bone grafts is used. In general, bone graft is either used en bloc (such as from the chin or the ascending ramus area of the lower jaw) or particulated, in order to be able to adapt it better to a defect. Dental bone grafting is a specialized oral surgical procedure that has been developed to reestablish lost jawbone. This loss can be a result of dental infection of abscess, periodontal disease, trauma, or the natural process of aging.
OD600 (Also written as O.D. 600, D600, o.d. 600, OD600) is an abbreviation indicating the optical density of a sample measured at a wavelength of 600 nm in 1 cm light path (unless otherwise stated). It is a commonly used in microbiology for estimating the concentration of bacteria or other cells in a liquid as the 600 nm wavelength does little to damage or hinder their growth. OD600 is a type of turbidity measurement. Since optical density in case of OD600 measurements results from light scattering by particles (cells) rather than absorption, size and shape as well as dead cells and debris of a cell may add to light dissipating. Distinctive cell types that are at densities of the same level (eg. cell/mL), may, therefore, show varying values OD600, when estimated on a similar instrument. For turbid samples such as cell cultures, the major contributor for the optical density measured is light scattering and not the result of molecular absorption following the Beer-Lambert Law. The measurements are therefore depending on the optical setup of the spectrophotometer (distance between the cell holder and instrument exit slit, monochromator optics, slit geometry, etc.), different instrument types will most likely tend to give different OD600 readings for the same turbid sample. Measuring the change of the OD600 as a function of time (e.g. measuring of the growth curve) may indicate the growth phase of cultured cell population, i.e. whether it is in the lag phase, log phase, or stationary phase.
=== Marriages and children === Galloway has been married four times and has six children. In 1979, he married Elaine Fyffe, with whom he has a daughter. The couple separated in 1987 and divorced in 1999. In 1994, Galloway married Amineh Abu-Zayyad, a Palestinian biologist, in a non-legally binding Islamic ceremony; a legally binding civil ceremony followed in March 2000. Abu-Zayyad was granted a divorce in February 2009, after an estrangement of several years, on the grounds of "unreasonable behaviour"; her petition was not contested. Galloway married Rima Husseini, his former researcher, in a non-legally binding Islamic ceremony in 2005. Galloway had two sons with Husseini, who is from Lebanon. On 31 March 2012 he married his fourth wife, the Dutch–Indonesian anthropologist Putri Gayatri Pertiwi, then 27, in Amsterdam. The initial event was followed by a traditional Javanese wedding ceremony in Sumatra and a civil marriage at the House of Commons in September 2012. Pertiwi worked as a consultant for a Dutch research firm and as a co-presenter of Galloway's TV show Sputnik. The couple have three children.
Sources: en.wikipedia.org
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.