scholarly journals The effect of silica desiccation under different storage conditions on filter-immobilized environmental DNA

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Michael J. Allison ◽  
Jessica M. Round ◽  
Lauren C. Bergman ◽  
Ali Mirabzadeh ◽  
Heather Allen ◽  
...  

Abstract Objective Silica gel beads have promise as a non-toxic, cost-effective, portable method for storing environmental DNA (eDNA) immobilized on filter membranes. Consequently, many ecological surveys are turning to silica bead filter desiccation rather than ethanol preservation. However, no systematic evaluation of silica bead storage conditions or duration past 1 week has been published. The present study evaluates the quality of filter-immobilized eDNA desiccated with silica gel under different storage conditions for over a year using targeted quantitative real-time polymerase chain reaction (qPCR)-based assays. Results While the detection of relatively abundant eDNA target was stable over 15 months from either ethanol- or silica gel-preserved filters at − 20 and 4 °C, silica gel out-performed ethanol preservation at 23 °C by preventing a progressive decrease in eDNA sample quality. Silica gel filter desiccation preserved low abundance eDNA equally well up to 1 month regardless of storage temperature (18, 4, or − 20 °C). However only storage at − 20 °C prevented a noticeable decrease in detectability at 5 and 12 months. The results indicate that brief storage of eDNA filters with silica gel beads up to 1 month can be successfully accomplished at a range of temperatures. However, longer-term storage should be at − 20 °C to maximize sample integrity.

2020 ◽  
Author(s):  
Michael J Allison ◽  
Jessica M Round ◽  
Lauren C Bergman ◽  
Ali Mirabzadeh ◽  
Heather Allen ◽  
...  

Abstract Objective Silica gel beads have promise as a non-toxic, cost-effective, portable method for storing environmental DNA (eDNA) immobilized on filter membranes. Consequently, many ecological surveys are turning to silica bead filter desiccation rather than ethanol preservation. However, no systematic evaluation of silica bead storage conditions or duration past one week has been published. The present study evaluates the quality of filter-immobilized eDNA desiccated with silica gel under different storage conditions for over a year using targeted quantitative real-time polymerase chain reaction (qPCR)-based assays. Results While the detection of relatively abundant eDNA target was stable over 15 months from either ethanol- or silica gel-preserved filters at -20 and 4oC, silica gel out-performed ethanol preservation at 23oC by preventing a progressive decrease in eDNA sample quality. Silica gel filter desiccation preserved low abundance eDNA equally well up to 1 month regardless of storage temperature (18, 4, or -20oC). However only storage at -20oC prevented a noticeable decrease in detectability at 5 and 12 months. The results indicate that brief storage of eDNA filters with silica gel beads up to one month can be successfully accomplished at a range of temperatures. However, longer-term storage should be at -20oC to maximize sample integrity.


1992 ◽  
Vol 2 (3) ◽  
pp. 378-381 ◽  
Author(s):  
Luis Hernández-Rivera ◽  
Robert Mullen ◽  
Marita Cantwell

Asparagus (Asparagus officinalis L.) spears (cv. UC 157) trimmed to 20 cm were cooled 0, 4, 8, 12, 16, and 20 hours after harvest and evaluated for resistance to shear at 5 and 10 cm above the cut end immediately after cooling and during storage at 0.5, 2.5, and 5C. Resistance to shear increased during cooling delays and with time in storage. Initial cooling delays and simulated marketing conditions (transfer to 15C for 1 day) were the principal causes of increased resistance to shear. A 4-hour cooling delay resulted in an average 40% increase in resistance to shear. Transfer to 15C for 1 day resulted in a greater increase in shear force in the rapidly cooled than in the delayed-cooled spears. Increases in resistance to shear during storage varied from 0% to 50% and depended on the storage temperature, time, and the initial cooling delay. Spears trimmed to a green base showed less increase in shear force after storage than did spears trimmed to a white base. The visual quality of asparagus stored for 14 days was similar (excellent) among spears from different storage temperatures and between green- and white-base spears. Storage quality after 24 days had decreased more in spears stored at 5C than at 2.5 or 0.5C, and more in the green-base than the white-base spears.


2019 ◽  
Vol 62 (5) ◽  
pp. 1259-1268
Author(s):  
Soraya Shafiekhani ◽  
Jung Ae Lee ◽  
Griffiths G. Atungulu

Abstract. Regression analyses were performed to determine the storage conditions that exhibited the best outcomes for long-grain, hybrid milled rice yield and quality. This study evaluated mold population on rough rice, milled rice discoloration, and head rice yield (HRY) after storage of rough rice in airtight conditions at moisture contents (MCs) of 12.5%, 16%, 19%, and 21% wet basis and temperatures of 10°C, 15°C, 20°C, 27°C, and 40°C at two-week intervals for 12 weeks. The experiment used a popular long-grain hybrid rice cultivar (XL745). Rice lots were procured from fields with and without conventional treatment of the field with fungicide for plant disease management. Field treatment and no field treatment were considered as a block, and a Mann-Whitney test was conducted to determine effect. The response surface method, an extension of second-order polynomial regression, was used to examine optimal treatment conditions. Mold population and milled rice discoloration from a combination of storage conditions were predicted using regression models. The first-order and second-order terms of temperature indicated a nonlinear relationship between temperature and ln(discoloration). The MC was positively associated with ln(discoloration), but the degree of impact may change with temperature because the interaction term was significant. From the model evaluation (R2 and lack-of-fit test), the discoloration level is expected to be 57% (49% to 66% confidence interval) under conditions of 20% MC, 40°C, and nine weeks of storage for samples procured from fungicide-treated rice fields. This discoloration change is substantial compared to the initial discoloration of 9%. At high temperature (40°C) and MC (21%), discoloration started immediately after two weeks of storage. Anaerobic storage conditions impeded mold growth, especially at high storage temperature (40°C). Low mold populations were observed in rice stored at low MC (16%). According to the regression model, the critical storage temperature that may lead to discoloration is between 27°C and 40°C. Pre-harvest fungicide treatment of rice in the field for disease control significantly improved the HRY but had no significant influence on mold population or discoloration. This study suggests a range of storage conditions to prevent losses in milling yield and quality of rice. In addition, the studied storage conditions mimicked the typical conditions for on-farm, in-bin drying and storage in the U.S. Mid-South, especially for the top layers of rice inside the bin, and therefore provide an important reference for growers and rice processors using in-bin structures to manage the quality of long-grain hybrid rice. Keywords: Discoloration, Head rice yield, Mold population, Regression analysis, Rice quality, Rice storage.


Author(s):  
Amalia Piscopo, A. De Bruno, A. Zappia, Giuseppina Gioffre ◽  
Nicola Grillone, Rocco Mafrica, Marco Marco Poiana

The aim of this work was to evidence the effect of the olive storage temperature on the quality of the extracted oils from the cultivars Carolea and Ottobratica, grown in the South of Italy. Qualitative parameters of oils were evaluated by analysis of major and minor components, in particular free acidity, peroxide value, fatty acid composition, sterol composition, squalene content and total content of polyphenols, tocopherols and pigments. The total antioxidant activity of olive oils was evaluated by DPPH and ABTS assays. The response to the storage conditions applied to olives in terms of oil qualitative parameters was different between the cultivars. In Carolea oils the effect of the temperature was significant, whereas also the harvesting time and the storage times affected the general quality of Ottobratica oils.


2016 ◽  
Vol 141 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Yan Wang

Alternatives to ethoxyquin (Etq) are needed for controlling superficial scald of ‘Anjou’ european pears (Pyrus communis) during long-term storage. The current commercial standard storage conditions [Etq + −1 °C + controlled atmosphere (CA) with 1.5 kPa O2] reduced scald occurrence compared with control fruit (−1 °C + CA) during 6–8 months storage. At 1 °C in air, 1-methylcyclopropene (1-MCP) fumigation at 0.15 µL·L−1 at harvest was more efficient on reducing scald than Etq but did not prevent scald during 6–8 months storage. The 1-MCP-treated fruit at 1 °C in air developed their ripening capacity at 20 °C following 6–8 months storage but had deceased shipping ability (softening and yellowing of fruit). Although Etq inhibition of scald was associated with the inhibition of α-farnesene oxidation to conjugated trienols (CTols); 1-MCP reduced α-farnesene synthesis and thereby the availability of substrate to oxidize to CTols. CA storage at 1.5 kPa O2 totally prevented scald and retarded the loss of shipping ability without affecting the ripening capacity of 1-MCP-treated fruit at 1 °C through further decreases in the syntheses of ethylene, α-farnesene and CTols during 6–8 months storage. In addition, 1-MCP prevented a CA-induced disorder, pithy brown core (PBC), in ‘Anjou’ pears possibly through enhancing an oxidative/reductive metabolic balance during extended storage. In conclusion, the combinations of 1 °C + 1-MCP + CA is a potential commercial alternative to Etq for scald control while allowing the 1-MCP-treated ‘Anjou’ pears to recover ripening capacity during the shelf life period after 6–8 months storage.


2020 ◽  
pp. 1-5
Author(s):  
Ampofo-Asiama Jerry ◽  
Mamudu Hafusatu ◽  
Helen Oluchi Emeruwa ◽  
Owusu Fokuo Kant ◽  
Quaye Bright

Burkina, a drink prepared from millet and milk, is gaining economic attention in Ghana due to its perceived nutritious nature and high energy content. The drink which is produced on a small-scale is usually vended without proper control of storage conditions leading to rapid loss of quality. The objective of this study was to investigate the effect of storing burkina at different temperatures (4 and 30°C) on the microbial and physicochemical (pH, titratable acidity, brix and phenolic content) quality of the drink. The pH, titratable acidity, brix and phenolic content of freshly prepared burkina were 3.65, 0.49%, 2.05 and 0.26 mg GAE/100 g, respectively. Although, changes were observed, storage temperature did not have a significant effect on the physicochemical quality of burkina. The initial load of aerobic mesophiles, lactic acid bacteria, Enterobacteriaceae, and yeast and moulds in the freshly prepared Burkina were 6.45, 5.49, 2.58 and 4.45 log cfu/mL, respectively. Storage at the higher temperature resulted in an increased microbial load within 48 h, leading to faster spoilage, with only marginal increases observed at the lower storage temperature.


2021 ◽  
Vol 17 ◽  
Author(s):  
Tahereh Zadeh Mehrizi ◽  
Mehdi Shafiee Ardestani ◽  
Sedigheh Amini Kafiabad

Background: Platelets are sensitive to chilling, therefore, the optimal storage temperature for maintaining normal function and structure in platelets is 22-24 °C up to 3-5 days. Introduction: Platelets are important blood cells involved in immunity, inflammation, and thrombosis. Today, platelet products are widely used to prevent bleeding in patients with thrombocytopenia and coagulopathy disorders. As a result, maintaining the quality of these products is very important. Method: In this review study, the reported influences of various dendrimers on platelets from 2001 to 2020 were investigated. Result: The results showed that positively charged dendrimers could cause platelet aggregation and activation during platelet storage time through their amine residues. In addition to surface charge, high generations, molecular weight and concentration are not recommended in the field of platelet storage and treatment. In contrast, negatively charged dendrimers, usually used at lower generations with proper molecular weight, lower size (less than 100 nm) and their carboxyl residues, cannot induce adverse effects on platelets during storage time. In addition, the results of this study revealed that PEGylation of dendrimers and platelets could improve platelet storage conditions. Conclusion: As anionic dendrimers can improve platelet storage time without inducing significant changes in morphology and function of platelets, they are recommended in the field of platelet storage and treatment.


2003 ◽  
Vol 12 (1) ◽  
pp. 47-49 ◽  
Author(s):  
Alessandro Bodini ◽  
Mariëlle W. H. Pijnenburg ◽  
Atillio L. Boner ◽  
Johan C. de Jongste

Background:Mylar balloons are used to collect exhaled air for analysis of fractional nitric oxide concentration (FENO).Aim:We studied the effect of storage conditions on the stability of nitric oxide (NO) in mylar balloons.Methods:Exhaled air samples and calibration gases were stored in mylar balloons at 4, 21 and 37°C, with or without silica gel. NO was measured after 0, 6, 9, 24 and 48 h. Scheffe F-tests were used to compare NO values. Results NO remained stable in balloons for 9 h at all temperatures, without silica gel. NO increased between 9 and 48 h, but only with low initial FENO. Silica gel increased variability.Conclusions:FENO in mylar balloons is stable for at least 9 h. The storage temperature is not critical, but silica gel increases variability.


2021 ◽  
Author(s):  
Tobias Guldberg Frøslev ◽  
Rasmus Ejrnæs ◽  
Anders Johannes Hansen ◽  
Hans Henrik Bruun ◽  
Ida Broman Nielsen ◽  
...  

Biodiversity of soil microbiota is routinely assessed with environmental DNA-based methods, among which amplification and massive parallel sequencing of marker genes (eDNA metabarcoding) is the most common. Soil microbiota may for example be investigated in relation to biodiversity research or as a tool in forensic investigations. After sampling, the taxonomic composition of soil biotic communities may change. In order to minimize community changes after sampling, it is desirable to reduce biological activity, e.g. by freezing immediately after sampling. However, this may be impossible due to remoteness of study sites or, in forensic cases, where soil has been attached to a questioned item for protracted periods of time. Here we investigated the effect of storage duration and conditions on the assessment of the soil biota with eDNA metabarcoding. We extracted eDNA from freshly collected soil samples and again from the same samples after storage under contrasting temperature conditions. We used five different primer sets targeting bacteria, fungi, protists (cercozoans), general eukaryotes, and plants. For these groups, we quantified differences in richness, evenness and community composition. Subsequently, we tested whether we could correctly infer habitat type and original sample identity after storage using a large reference dataset. We found increased community composition differences with extended storage time and with higher storage temperature. However, for samples stored less than 28 days at a maximum of 20 C, changes were generally insignificant. Classification models could successfully assign most stored samples to their exact location of origin and correct habitat type even after weeks of storage. Even samples showing larger compositional changes generally retained the original sample as the best match (relative similarity). Our results show that for most biodiversity and forensic applications, storage of samples for days and even several weeks may not be a problem, if storage temperature does not exceed 20 C. Even after suboptimal storage conditions, significant patterns can be reproduced.


2021 ◽  
Vol 4 ◽  
Author(s):  
Philippe Blancher ◽  
Estelle Lefrançois ◽  
Frederic Rimet ◽  
Agnès Bouchez

Recent developments in the use of environmental DNA are opening up new horizons for the assessment of the quality of aquatic environments. These rapid and cost-effective methods, in very swift progress, will potentially offer the opportunity to identify all the taxa present in an environmental sample (water or biota) by the use of complementary markers. The produced inventories can then be used for the assessment of biodiversity and ecological quality. However, the inclusion of these new DNA-based methods in monitoring practices is not straightforward and requires harmonised actions in the coming years at national and international levels. In order to foresee and stimulate such a harmonised implementation, the European network DNAqua-Net (COST Action CA15219) brought together some of its members, experts of ECOSTAT and other environmental biomonitoring stakeholders from different European countries. Through workshops, bringing together 51 participants in 7 sub-groups in April 2020, an implementation roadmap was designed. The coordinated actions to be taken in the different countries, and the possible collaborations and steps to be taken at the EU level were identified. This presentation will give an overview of all discussions (Lefrançois et al. 2020) reflecting the diversity of situations in Europe, as well as common views. We will highlight important actions required for a successful implementation of DNA-based biomonitoring of aquatic ecosystems to the horizon of 2030.


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