Effects of Storage Temperature and Media/Buffer for SARS-CoV-2 Nucleic Acid Detection

Abstract Objectives The increase in the number of patients with coronavirus disease 2019 (COVID-19) has delayed real-time reverse transcription–quantitative polymerase chain reaction (RT-qPCR), requiring proper shipping and storage conditions, especially in hot weather. This study aims to assess how some conditions, such as storage period, temperature, media or buffer, and sample types, affect the results of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-qPCR. Methods SARS-CoV-2–positive specimens were collected from Boramae Medical Center for 2 months (from May to June 2020) and stored in different media or buffers at different temperatures. Results As a result of examining confirmed patient samples, RT-qPCR results were not significantly affected by 2°C to 8°C storage until after 7 days. When stored at 20°C to 22°C or above 35°C, the results were affected negatively even after 1 day. Higher storage temperatures resulted in a lower probability of detecting viral nucleic acids because of degradation. Samples stored in pH-controlled media or buffer were more stable than those stored in nonbuffer states. Conclusions These results emphasize the importance of storage temperature and media or buffer and performing RT-qPCR for SARS-CoV-2 nucleic acid detection as soon as possible after sample collection.

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Influence of Storage Conditions on SARS-CoV-2 Nucleic Acid Detection in Throat Swabs

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa272 ◽

2020 ◽

Vol 222 (2) ◽

pp. 203-205 ◽

Cited By ~ 5

Author(s):

Lin Li ◽

Xiao Li ◽

Zhendong Guo ◽

Zhongyi Wang ◽

Ke Zhang ◽

...

Keyword(s):

Nucleic Acid ◽

Storage Time ◽

Storage Temperature ◽

Storage Conditions ◽

Nucleic Acid Detection ◽

Nucleic Acid Testing ◽

Threshold Values ◽

Sample Storage ◽

Cycle Threshold ◽

And Storage

Abstract The detection of SARS-CoV-2 infection is the premise of quarantine. In many countries or areas, samples need to be shipped or inactivated before SARS-CoV-2 testing. In this study, we checked the influence of sample storage conditions on SARS-CoV-2 nucleic acid testing results, including sample inactivation time, storage temperature, and storage time. All of these conditions caused an increase in the cycle threshold values of the nucleic acid tests and led to the misclassification of at least 10.2% of positive cases as negative or suspected. The results highlight the importance of immediate testing of samples for SARS-CoV-2 nucleic acid detection.

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The use of postharvest treatments to extend storage life and to control postharvest wastage of honeydew melons (Cucumis melo L. var. inodorus Naud.) in cool storage

Australian Journal of Experimental Agriculture ◽

10.1071/ea9900693 ◽

1990 ◽

Vol 30 (5) ◽

pp. 693 ◽

Cited By ~ 7

Author(s):

ME Edwards ◽

RM Blennerhassett

Keyword(s):

Water Loss ◽

Cucumis Melo ◽

Storage Temperature ◽

Chilling Injury ◽

Storage Period ◽

Storage Conditions ◽

Storage Life ◽

Storage Rots ◽

Wax Coating ◽

Cucumis Melo L

Three trials were undertaken to study storage conditions and handling procedures required to maximise the postharvest storage life of honeydew melons (Cucumis melo L. var. inodorus Naud.).Honeydew melons treated with chlorine (1000 mg/L), benomyl (250 mg/L) + guazatine (500 mg/L), shrink wrap (17 ym Cryovac XDR film), Semperfresh, wax, or combinations of these treatments were stored at 4 or 8�C, for 4 or 6 weeks. Benomyl plus guazatine reduced the development of storage rots associated with Alternaria and Fusarium spp. The use of shrink wrap and wax reduced water loss by melons but increased fungal infection in some cases. Shrink wrapping combined with the fungicide treatment effectively reduced the incidence of fungal breakdown in the storage period for up to 4 weeks. Wax coating with full strength Citruseal wax caused anaerobic tissue breakdown. Melons were affected by chilling injury at 4�C. Control of bacterial rots with benomyl + guazatine or with chlorine was variable. Semperfresh did not reduce the incidence of fungal breakdown or water loss from the melons. The results indicate that storage of honeydew melons for 4 weeks at 8�C by pretreating with fungicide is possible but the melons soften and rot after 6 weeks, making them unsaleable. Four weeks should be adequate to allow for sea freighting of honeydew melons to markets in South East Asia. Further research is required to determine the optimum storage temperature for honeydew melons.

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Thermal and temporal stability on the enteric viruses infectivity in surface freshwater

Water Science & Technology Water Supply ◽

10.2166/ws.2015.171 ◽

2015 ◽

Vol 16 (3) ◽

pp. 620-627 ◽

Cited By ~ 4

Author(s):

V. Moresco ◽

N. A. Damazo ◽

C. R. M. Barardi

Keyword(s):

Storage Temperature ◽

Quantitative Polymerase Chain Reaction ◽

Temporal Stability ◽

Enteric Viruses ◽

Human Adenovirus ◽

Adenovirus Type ◽

Storage Conditions ◽

Murine Norovirus ◽

Log Reduction ◽

The Stability

The present study aimed to evaluate the stability of Human Adenovirus type 2 (HAdV2) and Murine Norovirus 1 (MNV-1) in surface freshwater samples stored at different temperatures. For HAdV2 the stability decreased with increasing temperatures (−80 > −20 > 4 > 22 °C). The time required to reach one log reduction in viral titers (T90) was similar among all the times and temperatures by different cell-culture based methods and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The HAdV2 stability decreased with the time of storage temperature and methods employed, aside from samples stored at 22 and 4 °C which showed the lowest T90 values (50 days). For MNV-1, the samples stored at 22 and −20 °C showed higher log10 decay values, followed by 4 and −80 °C; while genome persistence was ranked as −80 > −20 > 4 > 22 °C. The T90 values were lower for samples stored at 22 °C (33 days), followed by 4, −20 and −80 °C with 111, 100 and 333 days, respectively. The results indicate that, under laboratory storage conditions, freshwater samples should be kept at 4 °C and at −80 °C for short- and long-term periods, respectively. This study provided useful information about thermal and temporal stability of the enteric viruses regarding sample storage conditions.

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Rapid Bedside Inactivation of Ebola Virus for Safe Nucleic Acid Tests

Journal of Clinical Microbiology ◽

10.1128/jcm.00346-16 ◽

2016 ◽

Vol 54 (10) ◽

pp. 2521-2529 ◽

Cited By ~ 10

Author(s):

Maiken Worsøe Rosenstierne ◽

Helen Karlberg ◽

Karoline Bragstad ◽

Gunnel Lindegren ◽

Malin Lundahl Stoltz ◽

...

Keyword(s):

Nucleic Acid ◽

Ebola Virus ◽

Storage Temperature ◽

Nucleic Acid Detection ◽

Blood Collection ◽

Acid Extraction ◽

Simple Method ◽

Virus Rna ◽

Vacuum Tubes ◽

Nucleic Acid Tests

Rapid bedside inactivation of Ebola virus would be a solution for the safety of medical and technical staff, risk containment, sample transport, and high-throughput or rapid diagnostic testing during an outbreak. We show that the commercially available Magna Pure lysis/binding buffer used for nucleic acid extraction inactivates Ebola virus. A rapid bedside inactivation method for nucleic acid tests is obtained by simply adding Magna Pure lysis/binding buffer directly into vacuum blood collection EDTA tubes using a thin needle and syringe prior to sampling. The ready-to-use inactivation vacuum tubes are stable for more than 4 months, and Ebola virus RNA is preserved in the Magna Pure lysis/binding buffer for at least 5 weeks independent of the storage temperature. We also show that Ebola virus RNA can be manually extracted from Magna Pure lysis/binding buffer-inactivated samples using the QIAamp viral RNA minikit. We present an easy and convenient method for bedside inactivation using available blood collection vacuum tubes and reagents. We propose to use this simple method for fast, safe, and easy bedside inactivation of Ebola virus for safe transport and routine nucleic acid detection.

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A Ligation/Recombinase Polymerase Amplification Assay for Rapid Detection of SARS-CoV−2

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.680728 ◽

2021 ◽

Vol 11 ◽

Author(s):

Pei Wang ◽

Chao Ma ◽

Xue Zhang ◽

Lizhan Chen ◽

Longyu Yi ◽

...

Keyword(s):

Nucleic Acid ◽

Rapid Detection ◽

Simple Procedure ◽

Quantitative Polymerase Chain Reaction ◽

Recombinase Polymerase Amplification ◽

Clinical Samples ◽

Nucleic Acid Detection ◽

High Concentration ◽

Sample Processing ◽

Low Efficiency

The pandemic of COVID-19 caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to more than 117 million reported cases and 2.6 million deaths. Accurate diagnosis technologies are vital for controlling this pandemic. Reverse transcription (RT)-based nucleic acid detection assays have been developed, but the strict sample processing requirement of RT has posed obstacles on wider applications. This study established a ligation and recombinase polymerase amplification (L/RPA) combined assay for rapid detection of SARS-CoV−2 on genes N and ORF1ab targeting the specific biomarkers recommended by the China CDC. Ligase-based strategies usually have a low-efficiency problem on RNA templates. This study has addressed this problem by using a high concentration of the T4 DNA ligase and exploiting the high sensitivity of RPA. Through selection of the ligation probes and optimization of the RPA primers, the assay achieved a satisfactory sensitivity of 101 viral RNA copies per reaction, which was comparable to RT-quantitative polymerase chain reaction (RT-qPCR) and other nucleic acid detection assays for SARS-CoV−2. The assay could be finished in less than 30 min with a simple procedure, in which the requirement for sophisticated thermocycling equipment had been avoided. In addition, it avoided the RT procedure and could potentially ease the requirement for sample processing. Once validated with clinical samples, the L/RPA assay would increase the practical testing availability of SARS-CoV-2. Moreover, the principle of L/RPA has an application potential to the identification of concerned mutations of the virus.

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Postharvest properties of sweet cherry fruit depending on rootstock and storage conditions

Folia Horticulturae ◽

10.1515/fhort-2017-0011 ◽

2017 ◽

Vol 29 (2) ◽

pp. 113-121 ◽

Cited By ~ 2

Author(s):

Ewa Dziedzic ◽

Jan Błaszczyk ◽

Elżbieta Kaczmarczyk

Keyword(s):

Sweet Cherry ◽

Storage Temperature ◽

Storage Period ◽

Storage Conditions ◽

Quality Parameters ◽

Soluble Solids ◽

Soluble Solids Content ◽

Fruit Storage ◽

Solids Content ◽

And Storage

ABSTRACT‘Regina’ sweet cherry fruit (Prunus avium L.) harvested from trees grown on vigorous and semi-dwarfing rootstocks was stored in normal atmosphere (NA) at 8°C and 2°C, and in a controlled atmosphere (CA) 3% O2 + 5% CO2at 2°C for two weeks. At harvest time, the fruits differed in the measured quality parameters (firmness, soluble solids content - SSC, titratable acidity - TA) depending on the rootstock. The storage conditions and the rootstocks significantly influenced the fruit quality parameters after storage. Generally, reduced fruit firmness and TA, and higher SSC and SSC/TA ratio were observed at the end of the storage period. Among the rootstocks, the lowest soluble solids content was found in the fruit from trees on the vigorous F12/1 rootstock. The lower storage temperature decreased the SSC independently of the storage atmosphere composition. Firmer fruit was found in CA 2°C compared with the other two treatments. The greatest loss of weight was found after fruit storage in NA 8°C. The extent of fruit decay depended on the season, storage conditions and the rootstock. Storage in NA 8°C of the fruit grown on F12/1 rootstock resulted in the highest percentage of fungal decay. The best retention of the green colour of the peduncle was noted in CA 2°C. The findings on how the rootstocks affect sweet cherry fruit properties can be useful for sweet cherry breeding programmes, as well as for sweet cherry crop production and storage technologies.

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Comparison of throat swabs and sputum specimens for viral nucleic acid detection in 52 cases of novel coronavirus (SARS-Cov-2) infected pneumonia (COVID-19)

10.1101/2020.02.21.20026187 ◽

2020 ◽

Cited By ~ 9

Author(s):

Chenyao Lin ◽

Jie Xiang ◽

Mingzhe Yan ◽

Hongze Li ◽

Shuang Huang ◽

...

Keyword(s):

Nucleic Acid ◽

Detection Efficiency ◽

Nucleic Acid Detection ◽

Sample Collection ◽

Pcr Assay ◽

Viral Nucleic Acid ◽

Detection Rates ◽

Qrt Pcr ◽

Positive Rate ◽

Novel Coronavirus

AbstractBackgroundIn December 2019, a novel coronavirus (SARS-CoV-2) infected pneumonia (COVID-19) occurred in Wuhan, China. Diagnostic test based on real-time reverse transcription polymerase chain reaction assay (qRT-PCR) was the main means of confirmation, and sample collection was mostly throat swabs, which was easy to miss the diagnosis. It is necessary to seek specimen types with higher detection efficiency and accuracy.MethodsPaired specimens of throat swabs and sputum were obtained from 54 cases, and RNA was extracted and tested for 2019-nCoV (equated with SARS-CoV-2) by qRT-PCR assay.ResultsThe positive rates of 2019-nCoV from sputum specimens and throat swabs were 76.9% and 44.2%, respectively. Sputum specimens showed a significantly higher positive rate than throat swabs in detecting viral nucleic acid using qRT-PCR assay (P=0.001).ConclusionsThe detection rates of 2019-nCoV from sputum specimens are significantly higher than throat swabs. We suggest that sputum would benefit for the detection of 2019-nCoV in patients who produce sputum. The results can facilitate the selection of specimens and increase the accuracy of diagnosis.

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Relationship of temperature and length of storage on ph of internal contents of chicken table egg in humid tropics

Biotechnology in Animal Husbandry ◽

10.2298/bah1603285m ◽

2016 ◽

Vol 32 (3) ◽

pp. 285-296 ◽

Cited By ~ 1

Author(s):

Ayoola Mathew ◽

Alabi Olufemi ◽

Aderemi Foluke ◽

Oguntunji Abel

Keyword(s):

Shelf Life ◽

Storage Temperature ◽

Storage Period ◽

Storage Conditions ◽

Humid Tropics ◽

Ph Values ◽

Randomized Design ◽

Internal Properties ◽

Relationship Of ◽

And Storage

All foods have limited shelf life which vary depending on the food and storage conditions. Table eggs are perishable food and storage temperature is an important factor that affects the shelf life. In tropical countries like Nigeria, eggs are usually preserved under ambient condition due to erratic power supply, which reduces the efficiency of refrigeration system. The aim of the present study was to examine the effects of storage periods, temperature and their relationship on the pH of chicken egg internal properties (yolk, albumen and whole egg). Fresh chicken table eggs were randomly allotted to three treatments of storage temperatures; refrigerator (40C ? 2), laboratory (320c ? 4), and poultry store room (370C ? 4). Eggs were assigned to treatments in a completely randomized design, and each treatment was replicated thrice. The pH was measured daily for each storage temperature in all treatments. Storage temperature and periods had significant (P<0.05) effect on pH of measured parameters. The pH values increased with storage temperature and period of storage. The rate of pH increase was significantly (P<0.05) higher in ambient as compared to refrigerator temperature. In this study, only the refrigerator storage has pH values within the range for fresh table eggs. At storage period above three weeks, pH values increased beyond the range for fresh egg. It is validated that storage temperature and period affected egg shelf life, the rate of freshness reduced with increased temperature, thus, storage beyond three weeks of ambient temperature is not advisable in humid tropics.

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Efficacy of the Antigenicity-Retaining Ability of Fixative Solutions for Liquid-Based Cytology: Immunocytochemistry of Long-Term Storage

Acta Cytologica ◽

10.1159/000518452 ◽

2021 ◽

pp. 1-12

Author(s):

Hiaki Sato ◽

Yoshiaki Norimatsu ◽

Satoshi Irino ◽

Takeshi Nishikawa

Keyword(s):

Cell Membrane ◽

Room Temperature ◽

Storage Temperature ◽

Storage Period ◽

Storage Conditions ◽

Immunocytochemical Staining ◽

Long Term Storage ◽

Liquid Based Cytology ◽

Term Storage

Introduction/Objective: Liquid-based cytology (LBC) is advantageous as multiple stained specimens can be prepared and used for additional assays such as immunocytochemical and molecular-pathological investigations. Two types of preservative-fixative solutions (fixatives) are used for nongynecologic specimens used in the BD SurePath-LBC (SP-LBC) method, and their components vary. However, few studies have evaluated the differences in antigen-retaining ability between these fixatives. Therefore, we investigated and compared the antigen-retaining ability of the fixatives in immunocytochemical staining (ICC) under long-term storage conditions. Materials and Methods: Sediments of cultured RAJI cells (derived from Burkitt’s lymphoma) were added to each fixative (red and blue) and stored at room temperature for a specified period (1 h; 1 week; and 1, 3, and 6 months). The specimens were then prepared using the SP-LBC method and subjected to ICC. Positivity rate was calculated using the specimens fixed at room temperature for 1 h as a control. Antibodies against Ki67 expressed in the nucleus and against CD20 and leukocyte common antigen (LCA) expressed on the cell membrane were used. Results: For CD20 and LCA, the positivity rate increased with time in the red fixative compared with that in the control. In the blue fixative, the positivity rate was highest at 1 h and was maintained at a high level throughout the storage period. In contrast, the Ki67 positivity rate was highest at 1 h in both red and blue fixatives and markedly decreased with time. Therefore, although refrigerated (8°C) storage was used, no improvement was noted. Conclusions: Long-term storage is possible for cell membrane antigens at room temperature; however, it is unsuitable for intranuclear antigens. Therefore, we conclude that suitable fixative type and storage temperature differ based on antigen location. Further investigation is warranted.

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Dependence of fat acidity value on wheat grain storage conditions

BIO Web of Conferences ◽

10.1051/bioconf/20201700107 ◽

2020 ◽

Vol 17 ◽

pp. 00107

Author(s):

I. A. Kechkin ◽

V. A. Ermolaev ◽

M. V. Ivanov ◽

A. I. Romanenko ◽

E. A. Gurkovskaya

Keyword(s):

Storage Temperature ◽

Storage Period ◽

Acid Value ◽

Storage Conditions ◽

Air Humidity ◽

Wheat Grain ◽

Storage Duration ◽

Long Term Storage ◽

Relative Air Humidity

The article presents the dependence of the fat acidity value (FAV) on the values of humidity and temperature, the relationship between the storage duration for wheat grain and FAV. To establish the expiration date of wheat grain during long-term storage, the author of the article considered the fat acid value (FAV) in mg of KOH. Storage temperature and relative air humidity in a desiccator affect the change (growth) of fat acidity value. The greatest changes occurred at 6th, 7th and 8th months of storage at a relative air humidity of more than 65 % and temperatures above 20 °C. At a storage temperature of 10 °C, in all cases the growth of FAV remained insignificant and was within the limits of determination accuracy. It is noted that when the relative humidity was below 60 %, while the temperature was the same as in the previous case, the FAV of wheat grain was practically unchanged through the 6-month storage period.

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