A practical reference on lyophilization: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-10 and is reviewed periodically as new material appears.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
==== Animal restraint ==== Large ranches and farms will generally use a squeeze chute to contain animals during branding. Livestock response to freeze branding is often so muted that ranchers report one leg restraint as being more than enough. Horse freeze branding is often accomplished with no more restraint than a twitch. This is a very different scenario from hot branding, where animals are often tied by all four legs to the bars of their squeeze chute to prevent the flight response from causing a misbrand.
Any single cycle is longer than 90 days, as long as the individual is at least one year post menarche. The cycle is generally shorter than 21 days or longer than 45 days, as long as the individual is at least one year post menarche. The cycle is generally longer than 35 days, as long as the individual is at least three years post menarche. Amenorrhea which is not due to another underlying cause, as long as the individual is at least 15 years old or at least 3 years post thelarche. Biochemical androgen excess in PMOS is assessed using total and free testosterone. Accurate measurement requires tandem mass spectrometry assays, as direct free testosterone tests are not reliable. Interpretation is based on laboratory reference ranges. Hormonal contraception can interfere with hormone levels, so a withdrawal period of at least three months with alternative contraception may be needed. Severely elevated androgen levels may indicate other conditions.
== Development of penicillin derivatives == The narrow range of treatable diseases or "spectrum of activity" of the penicillins, along with the poor activity of the orally active penicillin V, led to the search for derivatives of penicillin that could treat a wider range of infections. The isolation of 6-APA, the nucleus of penicillin, allowed for the preparation of semisynthetic penicillins, with various improvements over benzylpenicillin. Ampicillin was developed by the Beecham Research Laboratories in London. When introduced to clinical use in 1961 it was the first semisynthetic penicillin that could be taken orally that was effective against both Gram-negative and Gram-positive bacteria, whereas the original was only effective against Gram-positive.
Sources: en.wikipedia.org
== Business and philanthropy career == Pritzker co-founded Pritzker Group Private Capital with his brother Anthony Pritzker, serving as managing partner before stepping down in 2017 to run for governor. Anthony Pritzker reported that the Pritzker Group generated a return of 28.7% from 2007 to 2012, focusing on investing in family businesses and other entrepreneurial enterprises. In 2008, he received the Chicagoland Chamber of Commerce's Entrepreneurial Champion Award for his efforts to promote economic development and job creation. Pritzker served as chairman of ChicagoNEXT, then-Chicago Mayor Rahm Emanuel's Council on Innovation and Technology, and founded 1871, a nonprofit digital startup incubator, which, as of February 2025, had created 15,000 jobs and raised $4 billion in venture capital, according to a memo by its CEO, Betsy Ziegler. He was involved in the creation of the Illinois Venture Capital Association and the Chicagoland Entrepreneurial Center. He also co-founded Chicago Ventures and funded the startups Techstars Chicago and Built in Chicago. Pritzker is a member of the Illinois State Bar Association and the Chicago Bar Association. He has also been active in philanthropy. The J.B. and M.K. Pritzker Family Foundation, founded in 2001, has given millions of dollars to numerous causes, particularly early-childhood education. Most notably, in 2015, the foundation gave $100 million to the Northwestern Law School, which was renamed the Pritzker Law School.
=== Operation Enduring Freedom VI, 2005–2008 === The 1st Brigade of the 82nd deployed in April 2005 in support of OEF 6, and returned in April 2006. 1st Battalion, 325th Infantry Regiment deployed in support of OEF 6 from July through November 2005. In March 2006, 3rd Battalion (General Support), 82nd Aviation was selected to augment a special operations task force using CH-47 Chinooks and UH-60 Black Hawks. The task force consisted of 75th Ranger Regiment, Special Forces, and 160th Special Operations Aviation Regiment (Airborne). 2007 February 18, seven soldiers from the task force died in a helicopter crash. The deployment would end a month later (March 2007). In January 2007, then Maj. Gen. David M. Rodriguez deployed the division headquarters to Bagram Air Base, Afghanistan, accompanied by 4th BCT and the Aviation Brigade, as Commander, Combined Joint Task Force-82 (CJTF-82) and Regional Command – East for Operation Enduring Freedom VIII. The 3d BCT, 10th Mountain Division (Light Infantry) was extended for 120 days to increase the troop strength against the Taliban spring offensive. Extended to 15-month deployment, 4th BCT, which included 1–508th Infantry Regiment, 2–508th Infantry Regiment, and 4–73rd Cavalry Regiment, 2–321st Field Artillery, and 782nd Brigade Support Battalion, was commanded by then Col. Martin P. Schweitzer and remained in Khowst Province from January 2007 until April 2008. The 2–508th IR worked to establish and maintain firebases in and around the Ghazni province while actively patrolling their operational area.
A 2013 review found the data too weak to support use of Chinese herbal medicine (CHM) for benign prostatic hyperplasia. A 2013 review found the research on the benefit and safety of CHM for idiopathic sudden sensorineural hearing loss is of poor quality and cannot be relied upon to support their use. A 2013 Cochrane review found inconclusive evidence that CHM reduces the severity of eczema. The traditional medicine ginger, which has shown anti-inflammatory properties in laboratory experiments, has been used to treat rheumatism, headache and digestive and respiratory issues, though there is no firm evidence supporting these uses. A 2012 Cochrane review found no difference in mortality rate among 640 SARS patients when Chinese herbs were used alongside Western medicine versus Western medicine exclusively, although they concluded some herbs may have improved symptoms and decreased corticosteroid doses. A 2012 Cochrane review found insufficient evidence to support the use of TCM for people with adhesive small bowel obstruction. A 2011 review found low quality evidence that suggests CHM improves the symptoms of Sjögren's syndrome. A 2011 Cochrane review found inconclusive evidence to support the use of TCM herbal medicines for treatment of hypercholesterolemia. A 2011 Cochrane review did not find improvement in fasting C-peptide when compared to insulin treatment for latent autoimmune diabetes in adults after 3 months. It is important to highlight that the studies available to be included in this review presented considerable flaws in quality and design.
Lore Alford Rogers (7 February 1875 – 21 March 1975) was an American bacteriologist and dairy scientist. He is credited with discovering that butter made from pasteurized sweet cream remained fresher than that made from sour ripened cream, while suggesting that surplus milk could still be sold as concentrated sour milk products. He refined the steps for manufacture of high quality Swiss cheese and, new to the United States, production of Roquefort cheese. He was instrumental in finding ways to discourage fungal growth in sweetened condensed milk and preventing losses in evaporated milk from heat coagulation. Rogers' pioneering work on freeze drying bacterial cultures had immediate applications in World War I. As Chief of the Research Laboratories of the Bureau of Dairy Industry, USDA for nearly four decades, Rogers was praised for a leadership style that allowed the "creativity of others" to be "developed and expressed." In retirement he gave back to his own community by co-founding the Patten Lumbermen's Museum.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.