A practical reference on low-binding tubes: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-22. Anything still debated is marked as such rather than presented as settled.
Reconstitution is often performed with sterile water, buffer, or a water-miscible organic solvent, depending on solubility. The solvent should be added gently along the vial wall, and the solution mixed by gentle swirling rather than vigorous vortexing, which can cause foaming and surface denaturation. Some sequences require a small amount of base or acid to dissolve, followed by pH adjustment. Preparing a concentrated stock solution can simplify later dilution, but the stock itself may have limited stability. Records of solvent, concentration, and date support reproducibility.
After reconstitution, dividing the solution into single-use aliquots limits multiple warming and cooling events and reduces contamination risk. Low-binding polypropylene tubes are often preferred because peptides can adsorb to glass or untreated plastic surfaces. Filling headspace with nitrogen or argon can slow oxidation, and amber or foil-wrapped containers reduce photodegradation. Each aliquot should be labeled with peptide identity, concentration, date, and storage conditions. Frozen aliquots should be thawed quickly and kept on ice until use.
After reconstitution, solutions are divided into single-use aliquots and stored at -80°C. Labels include peptide name, concentration, buffer composition, date, and lot number. Freeze-thaw cycles are minimized by thawing only the needed aliquot on ice or at room temperature. Some peptides benefit from the addition of a carrier protein, such as bovine serum albumin, or a cryoprotectant like glycerol to reduce adsorption to plastic. Glass vials with low-binding surfaces are preferred for dilute solutions. Shipping of frozen aliquots uses dry ice and insulated containers to maintain the cold chain.
Receiving a peptide shipment requires immediate inspection of the packaging and temperature indicators. Any deviation from the specified cold chain should be documented and investigated. Upon arrival, solid peptides are generally kept at -20°C, whereas liquid formulations are stored at -80°C. Vials should be kept upright and protected from light. Repeated warming and cooling of the entire container is avoided by preparing smaller working aliquots. A log of lot numbers, receipt dates, and storage locations supports traceability and quality control.
Reconstitution is a critical handling step. The appropriate solvent—often sterile water, phosphate-buffered saline, or a water-acetonitrile mixture—is chosen based on peptide solubility. Adding solvent gently down the vial wall and swirling, rather than vortexing, reduces foaming and shear stress. The resulting solution should be clear; visible particles indicate incomplete dissolution or contamination. Concentration is recorded accurately because it affects subsequent use. If the peptide is not fully soluble, a small amount of organic solvent or a different buffer may be required, but this changes the final composition.
| Property | Value | Notes |
|---|---|---|
| Container material | Type I borosilicate glass or polypropylene | Low peptide adsorption; avoid untreated polystyrene for dilute solutions. |
| Headspace gas | Nitrogen or argon | Inert gas reduces oxidation for methionine- or cysteine-containing peptides. |
| Light exposure | Amber vial or foil wrap | Limits photodegradation of tryptophan, tyrosine, and phenylalanine residues. |
| Reconstitution solvent | Water, buffer, or water-miscible organic solvent | Choice depends on sequence charge and hydrophobicity; use highest available purity. |
| Aliquot size | Single-use portions | Minimizes warming and cooling cycles and cross-contamination between uses. |
Temperature is a primary variable because most degradation reactions slow as thermal energy decreases. Lyophilized powders are commonly held at -20 °C for routine work and at -80 °C for longer archival periods, though exact recommendations depend on the peptide. Solutions are less stable than dry powders in many cases, and repeated freeze-thaw cycles can promote aggregation or precipitation. Inert atmospheres, such as argon or nitrogen, can limit oxidation for oxygen-sensitive sequences. Desiccants reduce water activity, which lowers hydrolysis rates during storage.
Light exposure can damage aromatic residues and certain labels, so amber vials or opaque containers are often used. pH control matters in solution, as extreme acidity or alkalinity accelerates backbone cleavage; buffers may also introduce ions that affect solubility. Microbial growth is a concern for aqueous preparations that lack preservatives, though many research peptides are handled in sterile or low-bioburden conditions. Container materials can adsorb peptides, particularly hydrophobic or positively charged sequences, reducing recovery. These factors interact, meaning storage decisions balance chemical stability, physical state, and intended use.
Cold-chain shipping uses insulated containers, phase-change packs, and temperature indicators. Dry ice maintains -70 °C or lower but requires venting to avoid pressure buildup. Gel packs provide 2-8 °C for shorter transit. Upon arrival, recipients should record temperature indicators and transfer vials promptly to storage. Deviations from specified conditions should be documented and may require analytical re-check. The effect of a brief temperature excursion is peptide-specific and not always predictable from general rules.
Handling begins with receipt and inspection. Vials should be checked for damage, label integrity, and temperature history. Lyophilized peptides should be allowed to equilibrate to room temperature before opening to prevent condensation. Solutions should be prepared in a clean, calibrated environment using appropriate solvents. Personal protective equipment and containment reduce exposure and contamination. Documentation of lot number, date, and storage location supports traceability. The goal is to limit repeated temperature changes, moisture exposure, and microbial contamination.
Despite the acquisitions by big tobacco companies, some independent e-cigarette companies had more success, most notably Juul Labs, as of 2018. As of 2018, 95% of e-cigarettes were made in China. Despite international growth of e-cigarettes during the 2010s, not all regions around the world have yet embraced it as much. In 2018, Indonesia became only one of the first in Asia or the Global South to recognise e-cigarettes as a genuine alternative to smoking tobacco.
==== Obesity and osteoarthritis ==== Osteoarthritis and obesity are closely linked. Obesity is one of the most important preventable factors for the development of osteoarthritis. Originally, the relationship between osteoarthritis and obesity was considered to be exclusively biomechanically based, according to which the excess weight caused the joint to become worn down more quickly. However, today we recognise that there is also a metabolic component which explains why obesity is a risk factor for osteoarthritis, not only for weight-bearing joints (for example, the knees), but also for joints that do not bear weight (for example, the hands). Consequently, it has been shown that decreasing body fat lessens osteoarthritis to a greater extent than weight loss per se. This metabolic component related with the release of systemic factors, of a pro-inflammatory nature, by the adipose tissues, which frequently are critically associated with the development of osteoarthritis. Thus, the deregulated production of adipokines and inflammatory mediators, hyperlipidaemia, and the increase of systemic oxidative stress are conditions frequently associated with obesity, which can favour joint degeneration. Furthermore, many regulation factors have been implicated in the development, maintenance, and function, both of adipose tissues, as well as of the cartilage and other joint tissues. Alterations in these factors can be the additional link between obesity and osteoarthritis.
The use of basic technology is also a feature of nonhuman animal species. Tool use was once considered a defining characteristic of the genus Homo. This view was supplanted after discovering evidence of tool use among chimpanzees and other primates, dolphins, and crows. For example, researchers have observed wild chimpanzees using basic foraging tools, pestles, levers, leaves as sponges, and tree bark or vines as probes to fish termites. Western chimpanzees use stone hammers and anvils for cracking nuts, as do capuchin monkeys of Boa Vista, Brazil. Tool use is not the only form of animal technology use; for example, beaver dams, built with wooden sticks or large stones, are a technology with "dramatic" impacts on river habitats and ecosystems.
Arab immigration to Venezuela started as early as the 19th and 20th centuries, with migrants primarily hailing from the Ottoman provinces of Lebanon, Syria, and Palestine. They settled predominantly in Caracas, and have significantly influenced Venezuelan culture, particularly in terms of Arabic food and music. Religiously, the Arab-Venezuelans community consists mainly of Druze and Christians, who are affiliated with the Roman Catholic, Eastern Orthodox and Eastern Rite Catholic Churches. Venezuela hosts the largest Druze communities outside the Middle East, estimated at around 60,000 individuals. Most of them trace their ancestry back to Lebanon and Syria. More than 200,000 people from the As-Suwayda area hold Venezuelan citizenship, the majority of whom belong to the Syria's Druze sect and immigrated to Venezuela in the past century. The early Druze migrants to Venezuela assimilated well into the local population, with some even converting Catholicism. Nevertheless, many retained a strong Druze and Arab identity, along with adherence to Druze values. A prominent example of Druze influence in this Catholic country is the former vice president, Tareck El Aissami, who is of Druze descent. Other notable Venezuelan figures of Druze origin include Haifa El Aissami and Tarek William Saab.
The committee was composed of 16 experts, including leaders in clinical medicine medical research, economics, biostatistics, law, public policy, public health, and the allied health professions, as well as current and former executives from the pharmaceutical, hospital, and health insurance industries. The authors found major deficiencies in the current FDA system for ensuring the safety of drugs on the American market. Overall, the authors called for an increase in the regulatory powers, funding, and independence of the FDA. Some of the committee's recommendations were incorporated into drafts of the PDUFA IV amendment, which was signed into law as the Food and Drug Administration Amendments Act of 2007. As of 2011, Risk Minimization Action Plans (RiskMAPS) have been created to ensure risks of a drug never outweigh the benefits of that drug within the post-marketing period. This program requires that manufacturers design and implement periodic assessments of their programs' effectiveness. The Risk Minimization Action Plans are set in place depending on the overall level of risk a prescription drug is likely to pose to the public.
Sources: en.wikipedia.org
Tier 1: Tier 1 assembly is the standard Golden Gate assembly, and genes are assembled from their components parts (DNA parts coding for genetic elements like UTRs, promoters, ribosome binding sites or terminator sequences). Flanking the insertion site of the tier 1 destination vectors are a pair of inward cutting BpiI restriction sites. This allows these plasmids to be used as entry vectors for tier two destination vectors. Tier 2: Tier 2 assembly involves further assembling the genes assembled in tier 1 assembly into multi-gene constructs. If there is a need for further, higher tier assembly, inward cutting BsaI restriction sites can be added to flank the insertion sites. These vectors can then be used as entry vectors for higher tier constructs. Each assembly tier alternates the use of BsaI and BpiI restriction sites to minimise the number of forbidden sites, and sequential assembly for each tier is achieved by following the Golden Gate plasmid design. Overall, the MoClo standard allows for the assembly of a construct that contains multiple transcription units, all assembled from different DNA parts, by a series of one-pot Golden Gate reactions. However, one drawback of the MoClo standard is that it requires the use of 'dummy parts' with no biological function, if the final construct requires less than four component parts. The Golden Braid standard on the other hand introduced a pairwise Golden Gate assembly standard. The Golden Braid standard uses the same tiered assembly as MoClo, but each tier only involves the assembly of two DNA fragments, i.e. a pairwise approach.
== History == Naltrexone was first synthesized in 1963 by Metossian at Endo Laboratories, a small pharmaceutical company in New York City. It was characterized by Blumberg, Dayton, and Wolf in 1965 and was found to be an orally active, long-acting, and very potent opioid antagonist. The drug showed advantages over earlier opioid antagonists such as cyclazocine, nalorphine, and naloxone, including its oral activity, a long duration of action allowing for once-daily administration, and a lack of dysphoria, and was selected for further development. It was patented by Endo Laboratories in 1967 under the developmental code name EN-1639A and Endo Laboratories was acquired by DuPont in 1969. Clinical trials for opioid dependence began in 1973, and a developmental collaboration of DuPont with the National Institute on Drug Abuse for this indication started the next year in 1974. The drug was approved by the FDA for the oral treatment of opioid dependence in 1984, with the brand name Trexan, and for the oral treatment of alcohol dependence in 1995, when the brand name was changed by DuPont to Revia. A depot formulation for intramuscular injection was approved by the FDA under the brand name Vivitrol for alcohol dependence in 2006 and opioid dependence in 2010.
Omadacycline was statistically non-inferior to moxifloxacin at the early clinical response, 72 to 120 hours after therapy was initiated. In May 2016, a phase Ib study of omadacycline in urinary tract infection was initiated. In August 2016, a second phase III study of omadacycline was initiated in patients with acute bacterial skin and skin structure infections, comparing the efficacy and safety of once-daily, oral omadacycline to that of twice-daily, oral linezolid. In July 2017, analysis of the data showed that all of the primary and secondary endpoints required for submission to the FDA and European Medicines Agency were met. This was the third phase III registration study of omadacycline with favorable results.
== History == French pharmaceutical company Hoechst Marion Roussel (later Sanofi-Aventis) began phase II/III clinical trials of telithromycin (HMR-3647) in 1998. Telithromycin was approved by the European Commission in July 2001 and subsequently went on sale in October 2001. In the US, telithromycin received U.S. Food and Drug Administration (FDA) approval on April 1, 2004.
Sources: en.wikipedia.org
=== As a sawmill === When fastened into a special guide frame, a chainsaw can be used as a portable sawmill to cut bulk wood into planks or boards. Such usage is called a chainsaw mill or Alaskan sawmill.
=== Germany === In 2005, a product called Subyou was reportedly distributed from Germany on the Internet. The product was available in four flavors and packed in 65-gram, or possibly 100-gram, sachets. When mixed with 0.25 liters of water, it created a drink with 4.8% alcohol. It was assumed that a German producer manufactured the alcopop powder based on imported raw alcohol powder from the U.S. Later, Subyou disappeared and its website 'subyou.de' was taken down.
===== MeSH D08.811.464.257 – carbon-carbon ligases (EC 6.4) ===== MeSH D08.811.464.257.050 – acetyl-coa carboxylase MeSH D08.811.464.257.275 – polyketide synthases MeSH D08.811.464.257.500 – pyruvate carboxylase
== Purification == Purification of the receptor further verified its existence. The first attempt to purify the receptor involved the use of a novel opioid antagonist called chlornaltrexamine that was demonstrated to bind to the opioid receptor. Caruso later purified the detergent-extracted component of rat brain membrane that eluted with the specifically bound 3H-chlornaltrexamine.
On the day of discovery, 19 February, alpha irradiation of the einsteinium target occurred in three three-hour sessions. The cyclotron was in the University of California campus, while the Radiation Laboratory was on the next hill. To deal with this situation, a complex procedure was used: Ghiorso took the catcher foils (there were three targets and three foils) from the cyclotron to Harvey, who would use aqua regia to dissolve it and pass it through an anion-exchange resin column to separate the transuranium elements from the gold and other products. The resultant drops entered a test tube, which Choppin and Ghiorso took in a car to get to the Radiation Laboratory as soon as possible. Thompson and Choppin used a cation-exchange resin column and the α-hydroxyisobutyric acid. The solution drops were collected on platinum disks and dried under heat lamps. The three disks were expected to contain, respectively, the fermium, no new elements, and the mendelevium. Finally, they were placed in their own counters, which were connected to recorders such that spontaneous fission events would be recorded as huge deflections in a graph showing the number and time of the decays. There thus was no direct detection, but by observation of spontaneous fission events arising from its electron-capture daughter 256Fm. The first one was identified with a "hooray" followed by a "double hooray" and a "triple hooray". The fourth one eventually officially proved the chemical identification of the 101st element, mendelevium. In total, five decays were reported up until 4 a.m.
Sources: en.wikipedia.org
Dividing a stock into single-use portions usually reduces multiple thawing and refreezing events and lowers contamination risk. It also allows a needed amount to be removed without warming the entire supply.
Peptides can adsorb to some plastics and glass, especially at low concentrations, which reduces the measured amount in solution. Low-binding polypropylene tubes limit this loss and improve reproducibility.
Thawing on ice or in a cold water bath is generally preferred over rapid heating, which can accelerate degradation. Once thawed, the aliquot should be kept cold and used promptly rather than refrozen.
Common solvents include sterile water, phosphate-buffered saline, and water-acetonitrile mixtures. The choice depends on the peptide's solubility profile and the buffer compatibility for the intended application. Manufacturers often provide a recommended solvent on the product information sheet.