Everything below concerns GSSG. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-07-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
Stability depends on pH, temperature, oxygen exposure, and trace metals. Aqueous solutions of reduced glutathione are susceptible to oxidation, especially when neutral or alkaline and exposed to air. Transition metal ions can catalyze thiol oxidation, so chelators and inert atmospheres are sometimes used in research settings. Standards are typically stored cold and desiccated, with limited freeze-thaw cycles. Questions remain about how closely in vitro stability data reflect the behavior of glutathione within intact cells and tissues.
Measuring glutathione requires attention to oxidation during sample handling, because GSH in biological samples can convert to GSSG or form mixed disulfides with proteins after collection. Acidic extraction, rapid cooling, and chelating agents are commonly used to limit such changes. Analytical methods usually distinguish free reduced glutathione, total glutathione, and protein-bound forms. Because these forms have different stability and reactivity, reported values depend heavily on the preparation protocol. No single preparation is universally suitable for every biological matrix or analytical goal.
Several techniques are used for quantification. Enzymatic recycling assays rely on glutathione reductase and a colorimetric or fluorescent readout, offering sensitivity for total glutathione. High-performance liquid chromatography can separate GSH from GSSG and other thiols, often with UV, fluorescence, or electrochemical detection. Mass spectrometry provides structural confirmation and can quantify low-abundance species when paired with separation. Each approach has trade-offs in specificity, throughput, and equipment requirements, so method selection depends on the research question and available instrumentation.
Quality control for glutathione measurements includes calibration with authenticated standards, internal standards where available, blank correction, and spike recovery checks. Because glutathione can form during sample processing or degrade before analysis, pre-analytical handling is a major source of variability. Interlaboratory comparisons often show differences in reported values due to method-specific calibration and detection principles. Interpretive thresholds are context-dependent, and no single reference range applies across all tissues or matrices. Researchers generally report both reduced and oxidized forms, along with the method and sample handling details.
Quantification of glutathione in biological or food samples commonly uses liquid chromatography coupled to ultraviolet, fluorescence, electrochemical, or mass spectrometric detection. Because the thiol group oxidizes readily, samples are often acidified or derivatized immediately after collection to stabilize reduced glutathione. Enzymatic recycling assays and colorimetric kits offer higher throughput but generally lower specificity than chromatographic methods. Mass spectrometry can distinguish glutathione from related thiols and allow simultaneous measurement of oxidized forms. Reported concentrations depend strongly on sample type, extraction procedure, and analytical platform.
Glutathione reference materials are sensitive to oxygen, light, and elevated temperature. Solid material is typically stored desiccated at -20 °C or below, while solutions require tighter control because thiol oxidation proceeds faster in liquid form. Aqueous solutions are often prepared fresh, kept cold, and protected from air; some protocols add acid or chelating agents to slow metal-catalyzed oxidation. Repeated freeze-thaw cycles can accelerate degradation and should be avoided. Stability data vary by matrix, so laboratories usually verify performance with their own storage conditions.
| Property | Value | Notes |
|---|---|---|
| Reduced form | GSH | Main intracellular thiol |
| Oxidized form | GSSG | Disulfide dimer of two GSH molecules |
| Common separation method | Reversed-phase HPLC | Often with ion-pairing or derivatization |
| Typical detection | Fluorescence or mass spectrometry | UV detection is also used in some assays |
| Storage of standards | -20 °C or below, desiccated | Limit freeze-thaw and moisture exposure |
Quality control for glutathione focuses on identity, purity, and oxidation state. Certificates of analysis may report assay value, water content, and the presence of GSSG or other impurities. Chromatographic purity is often expressed as a percentage of peak area. Reference standards help laboratories compare results across instruments and batches. Because glutathione is a small, polar molecule, separation from cysteine, gamma-glutamylcysteine, and related thiols can be challenging. Verification often combines more than one analytical technique.
Measuring glutathione requires attention to sample preparation because the molecule oxidizes readily. Blood, tissue, and cell samples are often treated with acid to precipitate proteins and stabilize the thiol. Without such steps, GSH can convert to GSSG or form mixed disulfides during storage. Analytical methods include spectrophotometric assays, high-performance liquid chromatography, and mass spectrometry. Each approach has different sensitivity, specificity, and susceptibility to interference from related compounds in complex matrices.
For solid glutathione, storage conditions affect shelf life. The reduced form is typically kept cool, dry, and protected from air and light. Moisture can promote oxidation, while elevated temperatures accelerate degradation. Suppliers often specify storage at or below freezing, sometimes under inert gas. Solutions are less stable than powders and may require preparation shortly before use. Buffers and chelating agents can slow oxidation, but they do not eliminate it. Published stability data vary with matrix, pH, and container.
Enzymatic recycling assays provide a complementary approach for total glutathione. In these methods, glutathione reductase reduces oxidized glutathione while a thiol-reactive reagent, such as 5,5'-dithiobis(2-nitrobenzoic acid), produces a colored product. The reaction cycles between reduced and oxidized forms, amplifying the signal. Spectrophotometric or fluorometric detection can then estimate concentration. Distinguishing reduced glutathione from glutathione disulfide often requires separate aliquots, masking agents, or chromatographic separation, and the choice affects reported values.
Storage conditions strongly influence glutathione stability. The solid reduced form is commonly kept desiccated at or below minus twenty degrees Celsius, protected from light and moisture. Aqueous solutions are less stable because the thiol group reacts with dissolved oxygen, and oxidation accelerates at neutral or alkaline pH. Acidic solutions and oxygen-free handling can slow degradation, but repeated freeze-thaw cycles should be avoided. Researchers often verify concentration before use, because apparent losses can arise from oxidation or water uptake.
Measuring glutathione in biological samples requires attention to oxidation and matrix effects. High-performance liquid chromatography with ultraviolet or fluorescence detection can separate reduced and oxidized forms after derivatization. Liquid chromatography with tandem mass spectrometry offers higher specificity and can quantify glutathione alongside related thiols. Because glutathione can oxidize during sample handling, many protocols use rapid acidification with metaphosphoric acid or sulfosalicylic acid. Internal standards help correct for losses during extraction and analysis.
Commercial glutathione is available in research-grade, food-grade, and supplement-grade forms, and purity specifications differ accordingly. Certificates of analysis commonly report identity by nuclear magnetic resonance or mass spectrometry, purity by HPLC, residual solvents, and heavy metals. Reference standards with assigned purity support calibration, while isotopically labeled glutathione can serve as an internal standard for mass spectrometry. For supplements, label claims may not be independently verified, and regulatory oversight varies by country. Verification often involves third-party testing for identity, potency, and contaminants.
Quantifying glutathione requires distinguishing GSH from GSSG and preventing oxidation during sample preparation. Common approaches include the enzymatic recycling assay, often called the Tietze method, which measures total glutathione after converting GSSG to GSH. HPLC with ultraviolet or fluorescence detection and LC-MS/MS can separate and quantify both forms, sometimes after derivatization of the thiol group. Blood, plasma, and tissue samples differ in matrix and baseline concentrations, so method validation must account for recovery, linearity, and interference. No single assay is universally standard.
Quality control for glutathione materials checks identity, assay, purity, water content, and disulfide content. Commercial products vary from research-grade powder to dietary supplements, and labels may not distinguish reduced from oxidized forms. In the United States, oral glutathione is commonly sold as a dietary supplement rather than an approved drug, while injectable forms fall under different rules and may require a prescription. Regulatory status differs by country. Analytical certificates, when available, help verify what a material contains, but independent testing remains important for interpretation.
Laboratory measurement of glutathione typically starts with rapid acid extraction to prevent oxidation and enzymatic degradation. Common methods include enzymatic recycling assays, high-performance liquid chromatography, and liquid chromatography coupled with mass spectrometry. The recycling assay uses glutathione reductase and a thiol-reactive colorimetric or fluorescent reagent, measuring total glutathione after converting disulfide forms. Chromatographic methods can separate reduced and oxidized forms, which helps when the redox ratio is the target. Choice of method affects sensitivity, specificity, and the amount of sample needed.
Fresh frozen plasma is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. It is of critical importance in the treatment of many types of trauma which result in blood loss, and is therefore kept stocked universally in all medical facilities capable of treating trauma (e.g., trauma centers, hospitals, and ambulances) or that pose a risk of patient blood loss such as surgical suite facilities.
==== August ==== On 3 August, what the transitional government called "illegal groups" reportedly violated the ceasefire agreement and attacked the Syrian Internal Security Forces. Fighting took place in Tal al-Hadid, with the Al-Jabal Brigade involved in the fighting. On 8 August, clashes erupted in the town of Najran between Druze factions and an armed group, following an attack reportedly launched by the latter. The Syrian Observatory for Human Rights reported that the clashes resulted in the deaths of two people on both sides, along with material damage and the burning of several civilian homes, before the attackers withdrew. On 10 August, the town of al-Majdal came under an assault from three directions, involving the use of heavy machine guns and mortar fire. One wave of the attack originated from the town of al-Mazraa, where government forces are stationed, while the other two approached from positions west of al-Majdal, firing heavy and medium machine guns toward the surrounding villages. On 15 August, one woman from Suwayda was killed when unidentified armed assailants opened fire on the vehicle she was traveling in near the town of al-Kiheel in the eastern countryside of Daraa Governorate. She was en route with other passengers from Suwayda to Beirut via the highway passing through Daraa toward Damascus. The area where the incident took place was under the control of the Syrian government. On 16 August, demonstrations took place in al-Karama Square in Suwayda.
The suit also alleged that Theranos had misled company directors about its practices concerning laboratory testing and that it had secretly bought lab equipment to run fake demonstrations. On May 1, 2017, Theranos announced that it had reached an undisclosed settlement with Partner Fund Management LP (PFM). Theranos's General Counsel, David Taylor, stated: "Theranos is pleased to have resolved both lawsuits with PFM. Although we are confident that we would have prevailed at trial, resolution of these two cases allows our tender offer to go forward and enables us to return our focus where it belongs, which is on executing our business plans and delivering value for our shareholders." In April 2017, Theranos reached a settlement with CMS agreeing to stay out of the blood-testing business for at least two years in exchange for reduced penalties, and signed a consent decree with Arizona Attorney General Mark Brnovich over violations of the Arizona Consumer Fraud Act. Alleged violations included false advertisement and inaccurate blood testing. Theranos agreed to refund $4.65 million to the state's residents for Theranos blood testing services, providing a refund to every resident who had received a test, regardless of whether the test results were voided or corrected. In August 2017, Theranos announced it had reached a settlement with Walgreens. In December 2017, Fortress Investment Group, a wholly owned company of Softbank Group, loaned $100 million to Theranos for 4% of the company.
== Materials science == Materials science has applied the techniques of combinatorial chemistry to the discovery of new materials. This work was pioneered by P.G. Schultz et al. in the mid-nineties in the context of luminescent materials obtained by co-deposition of elements on a silicon substrate. His work was preceded by J. J. Hanak in 1970 but the computer and robotics tools were not available for the method to spread at the time. Work has been continued by several academic groups as well as companies with large research and development programs (Symyx Technologies, GE, Dow Chemical etc.). The technique has been used extensively for catalysis, coatings, electronics, and many other fields. The application of appropriate informatics tools is critical to handle, administer, and store the vast volumes of data produced. New types of design of experiments methods have also been developed to efficiently address the large experimental spaces that can be tackled using combinatorial methods.
=== Warfarin === Excessive use of alcohol is known to affect the metabolism of warfarin and can elevate the INR, and thus increase the risk of bleeding. The U.S. Food and Drug Administration (FDA) product insert on warfarin states that alcohol should be avoided. The Cleveland Clinic suggests that when taking warfarin one should not drink more than "one beer, 6 oz of wine, or one shot of alcohol per day".
Sources: en.wikipedia.org
=== China === As of March 2025, the government is estimated to have 401 million barrels stored in above-ground facilities and 668 million barrels in above-ground commercial storage. By December 2025, United States Energy Information Administration estimated Chinese held around 1.4 billion barrels of crude oil in reserve from both government-held and state-owned national oil companies (NOC) inventories, which are both part of the strategic reserves. Outside of the official strategic reserves, Chinese corporate and commercial refineries also have several hundred million barrels of crude oil. China hiked prices serveal times during the war, but due to queue forming in the gas stations in multiple Chinese cities, the Chinese government reduced its planned fuel price hikes. China's large strategic reserve helped the country insulate itself significantly from the 2026 Iran war and ensuing global fuel crisis. By late June 2026, China's strategic petroleum reserve (SPR) remained nearly unchanged after the Iran war. To ensure domestic supplies without using strategic reserve, China halted its supplies of refined oil products to other countries. China is a major oil refiner and exporter of petroleum products. On 5 March, major Chinese refiners, including China Petroleum & Chemical (Sinopec) and Rongsheng Petrochemical Co Ltd, were ordered by the government to stop accepting new fuel export contracts. Jet fuel refuelling for international flights and supplies to Hong Kong and Macau are exempt from this guidance.
From 2006 to 2013, Morgan was a cast member of the television series 30 Rock. He played the character Tracy Jordan, a caricature of himself. His work on 30 Rock was well-received, and he was nominated for Outstanding Supporting Actor in a Comedy Series at the 2009 Emmy Awards. He returned to the role in July 2020 for a reunion episode during the COVID-19 pandemic that was an upfront special for NBCUniversal. After 30 Rock, beginning in 2018, Morgan began starring in the TBS series The Last O.G. It ran for four seasons until 2021. Morgan also returned to host SNL on March 14, 2009, and reprised his roles as Brian Fellow and Astronaut Jones. He later made a guest appearance on the 2011 Christmas show, hosted by Jimmy Fallon, and again hosted the show on October 17, 2015. In addition to his television and comedy career, Morgan has acted in several comedy movies, alongside Adam Sandler, Eddie Murphy, and Will Ferrell. In Adam Sandler's film The Longest Yard, he plays a transgender inmate. He has also taken on a number of voice acting roles. He plays Spoonie Luv on the Comedy Central program Crank Yankers and as Woof in the animated series Where My Dogs At?. He also was the voice of Luis in the animated film Rio. Morgan has had a number of solo stand-up specials produced throughout his career. One Mic was produced and aired on Comedy Central in 2002. His other comedy specials include Tracy Morgan: Bona Fide in 2014 and Staying Alive in 2017, released after he was severely injured in a 2014 car accident.
=== Prevalence === Riboflavin deficiency is uncommon in the US and in other countries with wheat flour or corn meal fortification programs. From data collected in biannual surveys of the US population, for ages 20 and over, 22% of women and 19% of men reported consuming a supplement that contained riboflavin, typically a vitamin-mineral multi-supplement. For the non-supplement users, the dietary intake of adult women averaged 1.74 mg/day and men 2.44 mg/day. These amounts exceed the RDAs for riboflavin of 1.1 and 1.3 mg/day respectively. For all age groups, on average, consumption from food exceeded the RDAs. A 2001-02 US survey reported that less than 3% of the population consumed less than the Estimated Average Requirement of riboflavin.
Finally, the site is logistically essential for the Golden Dome's low-orbit interceptors that suffer high atmospheric drag and require continuous replenishment. Some strategic analyses speculate that Arctic basing could, in theory, support higher-latitude launch and tracking operations, though no such launch infrastructure currently exists in Greenland. Interest in Greenland's rare-earth elements has centered on the Tanbreez deposit. Defense analysts note that the deposit has tantalum and niobium and is uniquely rich in both zirconium and heavy rare earths like samarium and yttrium, the essential precursors for zirconium diboride (ZrB2) ultra-high temperature ceramics. These materials are required to help hypersonic glide weapons survive atmospheric re-entry temperatures. Forbes reported in January 2026 that billionaires including Jeff Bezos, Bill Gates, and Peter Thiel have accelerated investments in Greenlandic ventures such as KoBold Metals and Praxis, effectively betting that security mandates will override local environmental barriers to extraction.
Chemist Gary Molander of the University of Pennsylvania described how "[d]ozens of biotechnology and drug companies were started" based on Hirschmann's developments and that "[t]he whole biotechnology field" and new classes of medicines, such as protease inhibitors for the treatment of AIDS, were established through his approach. As head of Merck's department of new lead discovery starting in 1971 and as senior vice president for basic research in chemistry starting in 1978, serving until the retirement age of 65, when he left the firm in 1987, Hirschmann played a pivotal role in the development of many of the firm's products. Among the medications he was involved with was the development of the antiparasitic Ivermectin used for the treatment of river blindness, the statin Mevacor for reducing cholesterol in patients at risk of cardiovascular disease, the beta-lactam-family broad-spectrum antibiotic Primaxin, the synthetic androgen Proscar used for the treatment of enlarged prostate and prostate cancer and of the ACE inhibitor Vasotec for treating hypertension. Following his departure from Merck, Hirschmann taught at the University of Pennsylvania and the Medical University of South Carolina until his retirement in 2006.
Sources: en.wikipedia.org
Common methods include enzymatic recycling assays, liquid chromatography, and mass spectrometry. Many protocols separate reduced glutathione from its oxidized disulfide form before detection.
The ratio compares reduced glutathione with its oxidized dimer. It is used as an indicator of redox status, although the value depends strongly on sample handling and analytical method.
Glutathione can oxidize quickly after a sample is collected. Acidification, cooling, and chelators are often used to reduce artifactual changes before analysis.
Acidification lowers pH and helps prevent oxidation of the thiol group during extraction and storage. It can also precipitate proteins and stabilize the reduced form before analysis.