scholarly journals Simply saliva: stability of SARS-CoV-2 detection negates the need for expensive collection devices

Author(s):  
Isabel M Ott ◽  
Madison S Strine ◽  
Anne E Watkins ◽  
Maikel Boot ◽  
Chaney C Kalinich ◽  
...  

Most currently approved strategies for the collection of saliva for COVID-19 diagnostics require specialized tubes containing buffers promoted for the stabilization of SARS-CoV-2 RNA and virus inactivation. Yet many of these are expensive, in limited supply, and not necessarily validated specifically for viral RNA. While saliva is a promising sample type as it can be reliably self-collected for the sensitive detection of SARS-CoV-2, the expense and availability of these collection tubes are prohibitive to mass testing efforts. Therefore, we investigated the stability of SARS-CoV-2 RNA and infectious virus detection from saliva without supplementation. We tested RNA stability over extended periods of time (2-25 days) and at temperatures representing at-home storage and elevated temperatures which might be experienced when cold chain transport may be unavailable. We found SARS-CoV-2 RNA in saliva from infected individuals is stable at 4°C, room temperature (~19°C), and 30°C for prolonged periods and found limited evidence for viral replication in saliva. This work demonstrates that expensive saliva collection options involving RNA stabilization and virus inactivation buffers are not always needed, permitting the use of cheaper collection options. Affordable testing methods are urgently needed to meet current testing demands and for continued surveillance in reopening strategies.

BMJ Open ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. e029083 ◽  
Author(s):  
Tri-Hung Nguyen ◽  
Peter Lambert ◽  
Rajpreet Singh Minhas ◽  
Claire McEvoy ◽  
Kim Deadman ◽  
...  

IntroductionOxytocin, administered via injection, is recommended by WHO for the prevention and treatment of postpartum haemorrhage. However, the susceptibility of oxytocin injection to thermal degradation has led WHO and UNICEF to recommend cold-chain storage of all oxytocin products. Nevertheless, some oxytocin products supplied to the global market are labelled for storage at ≤25°C, often with a shorter shelf-life relative to products labelled for refrigeration. Differences in labelled storage requirements can lead to uncertainties among stakeholders around the relative stability of oxytocin products and specifically whether ≤25°C products are more resistant to degradation. Such confusion can potentially influence policies associated with procurement, distribution, storage and the use of oxytocin in resource-poor settings.ObjectivesTo compare the stability of oxytocin injection ampoules formulated for storage at ≤25°C with those labelled for refrigerated storage.DesignAccelerated and temperature cycling stability studies were performed with oxytocin ampoules procured by the United Nations Population Fund (UNFPA) from four manufacturers.MethodUsing oxytocin ampoules procured by UNFPA, accelerated stability (up to 120 days) and temperature cycling (up to 135 days between elevated and refrigerated temperatures) studies were performed at 30°C, 40°C and 50°C. Oxytocin content was quantified using a validated HPLC-UV method.ResultsAll ampoules evaluated exhibited similar stability profiles under accelerated degradation conditions with the exception of one product formulated for ≤25°C storage, where the rate of degradation increased at 50°C relative to other formulations. Similar degradation trends at elevated temperatures were observed during temperature cycling, while no significant degradation was observed during refrigerated periods of the study.ConclusionOxytocin ampoules formulated for non-refrigerated storage demonstrated comparable stability to those labelled for refrigerated storage and should not be interpreted by stakeholders as offering a more stable alternative. Furthermore, these products should not be procured for use in territories with high ambient temperatures, where all oxytocin injection products should be supplied and stored under refrigerated conditions.


2021 ◽  
Author(s):  
Yuan Carrington ◽  
Justin Orlino ◽  
Alejandro Romero ◽  
Jessica Gustin ◽  
Mahssa Rezaei ◽  
...  

AbstractCOVID-19 testing is not accessible for millions during this pandemic despite our best efforts. Without greatly expanded testing of asymptomatic individuals, contact tracing and subsequent isolation of spreaders remains as a means for control. In an effort to increase RT-PCR assay testing for the presence of the novel beta-coronavirus SARS-CoV-2 as well as improve sample collection safety, GenTegra LLC has introduced two products for saliva collection and viral RNA stabilization: GTR-STM™ (GenTegra Saliva Transport Medium) and GTR-STMdk™ (GenTegra Saliva Transport Medium Direct to PCR). Both products contain a proprietary formulation based on GenTegra’s novel “Active Chemical Protection™” (ACP) technology that gives non-dilutive, error-free saliva sample collection using RNA stabilization chemicals already dried in the collection tube.GTR-STM can be used for safer saliva-based sample collection at home (or at a test site). Following saliva collection, the sample-containing GTR-STM can be kept at ambient temperature during shipment to an authorized CLIA lab for analysis. SARS-CoV-2 viral RNA in GTR-STM is stable for over a month at ambient temperature, easily surviving the longest transit times from home to lab. GTR-STM enhances patient comfort, convenience, compliance and reduces infectious virus exposure to essential medical and lab professionals.Alternatively, the GTR-STMdk direct-into-PCR product can be used to improve lab throughput and reduce reagent costs for saliva sample collection and testing at any lab site with access to refrigeration. GTR-STMdk reduces lab process time by 25% and reagent costs by 30% compared to other approaches. Since GTR-STMdk retains SARS-CoV-2 viral RNA stability for three days at ambient temperature, it is optimized for lab test site rather than at home saliva collection. SARS-COV-2 viral RNA levels as low as 0.4 genome equivalents/uL are detected in saliva samples using GTR-STMdk. The increased sensitivity of SARS-CoV-2 detection can expand COVID-19 testing to include asymptomatic individuals using pooled saliva.One Sentence SummaryGTR-STM and Direct-into-PCR GTR-STMdk offer substantive improvements in SARS-CoV-2 viral RNA stability, safety, and RT-PCR process efficiency for COVID-19 testing by using a non-dilutive saliva sample collection system for individuals at home or onsite respectively.


2016 ◽  
Vol 113 (32) ◽  
pp. 8921-8926 ◽  
Author(s):  
Roland Bliem ◽  
Jessi E. S. van der Hoeven ◽  
Jan Hulva ◽  
Jiri Pavelec ◽  
Oscar Gamba ◽  
...  

Interactions between catalytically active metal particles and reactant gases depend strongly on the particle size, particularly in the subnanometer regime where the addition of just one atom can induce substantial changes in stability, morphology, and reactivity. Here, time-lapse scanning tunneling microscopy (STM) and density functional theory (DFT)-based calculations are used to study how CO exposure affects the stability of Pt adatoms and subnano clusters at the Fe3O4(001) surface, a model CO oxidation catalyst. The results reveal that CO plays a dual role: first, it induces mobility among otherwise stable Pt adatoms through the formation of Pt carbonyls (Pt1–CO), leading to agglomeration into subnano clusters. Second, the presence of the CO stabilizes the smallest clusters against decay at room temperature, significantly modifying the growth kinetics. At elevated temperatures, CO desorption results in a partial redispersion and recovery of the Pt adatom phase.


Author(s):  
Stephanie Saalfeld ◽  
Thomas Wegener ◽  
Berthold Scholtes ◽  
Thomas Niendorf

AbstractThe stability of compressive residual stresses generated by deep rolling plays a decisive role on the fatigue behavior of specimens and components, respectively. In this regard, deep rolling at elevated temperature has proven to be very effective in stabilizing residual stresses when fatigue analysis is conducted at ambient temperature. However, since residual stresses can be affected not only by plastic deformation but also when thermal energy is provided, it is necessary to analyze the influence of temperature and time on the relaxation behavior of residual stresses at elevated temperature. To evaluate the effect of deep rolling at elevated temperatures on stability limits under thermal as well as combined thermo-mechanical loads, the present work introduces and discusses the results of investigations on the thermal stability of residual stresses in differently deep rolled material conditions of the steel SAE 1045.


1999 ◽  
Vol 556 ◽  
Author(s):  
P. E. Raison ◽  
R. G. Haire ◽  
T. Sato ◽  
T. Ogawa

AbstractPolycrystalline pyrochlore oxides consisting of selected f elements (lanthanides and actinides) and Zr and Hf have been prepared and characterized. Characterization to date has been primarily by X-ray diffraction, both at room and at elevated temperatures. Initial studies concentrated on selected lanthanides and the Np, Pu and Am analogs (reported here) but have been extended to the other actinide elements through Cf. Data from these studies have been used to establish a systematic correlation regarding the fundamental materials science of these particular pyrochlores and structurally related fluorite-type dioxides. In addition to pursuing their materials science, we have addressed some potential technological applications for these materials. Some of the latter concern: (1) immobilization matrices; (2) materials for transmutation concepts; and (3) special nuclear fuel forms that can minimize the generation of nuclear wastes. For f elements that display both a III and IV oxidation state in oxide matrices, the synthetic path required for producing the desired pyrochlore oxide is dictated by their pseudo-oxidation potential the stability of the compound towards oxygen uptake. For the f elements that display an oxidationreduction cycle for pyrochlore-dioxide solid solution, X-ray diffraction can be used to identify the composition in the oxidation-reduction cycle, the oxygen stoichiometry and/or the composition. This paper concentrates on the Np, Pu and Am systems, and addresses the above aspects, the role of the crystal matrix in controlling the ceramic products as well as discussingsome custom-tailored materials.


Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 372-389
Author(s):  
João Paulo de Sousa Prado ◽  
José Marcelino Oliveira Cavalheiro ◽  
Thiago Brandão Cavalheiro ◽  
Fernanda Vanessa Gomes da Silva

The Brazilian shrimp farming uses mainly commercial feed for shrimp nutrition. This choice occurs because of the advantages related to convenience and good adaptation of Litopenaeus vannanmei to feed intake. Thus, the quality of feed is a determining factor for maximum performance of the shrimp farms, making the right selection of suppliers and control of the storage conditions as ways to prevent contamination and spoilage of feed. The objective of this study was to evaluate the stability of amino acids in meals and commercial feed with different protein levels, subjected to high-temperature storage. The samples were exposed to temperature of 50 oC and evaluated every 5 days for 30 days.The analyses of the degradation of amino acids were performed using an elution gradient in HPLC system.In evaluated meals it was observed that valine and arginine were the amino acids that suffered greater loss during the experiment and histidine and alanine suffered less degradation.Significant difference was observed in the content of all amino acids analyzed after exposure of the feed to the temperature of 50 oC; with reduce in values of its amino acid content. The results obtained in this study indicate that meals and feed exposed to elevated temperatures significantly reduced the content of its amino acids.


1989 ◽  
Vol 173 ◽  
Author(s):  
Michiya Otani ◽  
Sugio Otani

ABSTRACTThe stability of the magnetic properties of dehydrogenated triaryl-methane resins was investigated both at room temperature and at elevated temperatures. A magnetic property different from that reported in a previous paper was found in the course of studying the reproducibility of synthesis. This new property was examined through a mechanical response of the resins to a set of permanent magnets.


Author(s):  
Ivelin Pantchev ◽  
Goritsa Rakleova ◽  
Atanas Atanassov

Abstract The research community is deeply convinced that RNA is unstable in the environment. Its roots rise from numerous failed attempts to isolate functional cellular RNA molecules. Further support had originated from the fast turnover of RNA in the cells. The situation changed recently with the discovery that externally applied dsRNA can produce targeted gene silencing in plant-feeding insects. First results have demonstrated that external dsRNA can successfully pass the insect gastrointestinal tract and reach its final destination within the body cells. This was somewhat unexpected and sparked new interest in RNA stability in the environment and its fate in the insect organism. In this brief review we make an attempt to summarize current knowledge and to propose a model of how dsRNA can perform its function under these settings.


1997 ◽  
Vol 3 (S2) ◽  
pp. 673-674
Author(s):  
M. Rühle ◽  
T. Wagner ◽  
S. Bernath ◽  
J. Plitzko ◽  
C. Scheu ◽  
...  

Heterophase boundaries play an important role in advanced materials since those materials often comprise different components. The properties of the materials depend strongly on the properties of the interface between the components. Thus, it is important to investigate the stability of the microstructure with respect to annealing at elevated temperatures. In this paper results will be presented on the structure and composition of the interfaces between Cu and (α -Al2O3. The interfaces were processed either by growing a thin Cu overlayer on α- Al2O3 in a molecular beam epitaxy (MBE) system or by diffusion bonding bulk crystals of the two constituents in an UHV chamber. To improve the adhesion of Cu to α -Al2O3 ultrathin Ti interlayers were deposited between Cu and α - Al2O3.Interfaces were characterized by different transmission electron microscopy (TEM) techniques. Quantitative high-resolution electron microscopy (QHRTEM) allows the determination of the structure (coordinates of atoms) while analytical electron microscopy (AEM) allows the determination of the composition with high spatial resolution.


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