scholarly journals Influence of storage time and temperature on the activity of urease

2019 ◽  
Vol 51 (2) ◽  
pp. 159-163
Author(s):  
B. Alev ◽  
S. Tunali ◽  
R. Yanardag ◽  
A. Yarat
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Urease Activity ◽  
Storage Temperature ◽  
Practical Importance ◽  
Storage Conditions ◽  
Relative Activity ◽  
Significant Loss ◽  
Long Term Storage ◽  
Activity Measurements

Enzymes are made of protein, that is why they are sensitive molecules and are affected by storage conditions. A small change in enzyme activity during storage may cause a big error in analysis results. The aim of the study was to evaluate the effects of storage time and temperature on urease activity. Urease solutions were prepared at different activities (from 100 to 2000 U/mL) and stored at room temperature, in the refrigerator (4°C), and in the deep freezer (-18°C and -80°C). Activity measurements were made at regular intervals until 28 days by the modified Weatherburn method. The relative activities of 100-1000 U/mL urease solutions stored at room temperature, 4, -18 or -80°C were 75% and below after 4 days. Twenty-eight days later, for 2000 U/mL urease solutions, only at room temperature, the relative activity was reduced to 37%, while at 4, -18 or -80°C, the relative activities were above 80%. Since urease can be maintained at 4°C for 28 days without significant loss of activity, it has practical importance. Low-activity urease solutions (such as 100-1000 U/mL) should not be stored at -18 or -80°C for short or long term storage, they should be stored at 4°C only for one day. Keywords: Urease activity, storage time, storage temperature

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

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

<b><i>Introduction/Objective:</i></b> 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. <b><i>Materials and Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusions:</i></b> 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.

The Effect of Storage Temperature and Physical State on the Performance of Antisera in Radioimmunoassay after Long-Term Storage

1988 ◽  
Vol 25 (1) ◽  
pp. 89-95
Author(s):  
B A Middleton ◽  
L M Morgan ◽  
G W Aherne ◽  
V Marks
Keyword(s):  
Room Temperature ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Liquid Form ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Control Serum ◽  
Term Storage ◽  
Temperature Storage

The performance in radioimmunoassay of four antisera after storage at temperatures ranging from −40°C to room temperature, in three physical states (frozen, liquid or freeze dried) was investigated over a 3-year period. No deterioration in antiserum performance in terms of precision and accuracy of quality control serum measurement or recovery of ligand was apparent under any of the storage conditions studied. Some lowering of titre became apparent in two of the antisera over the study period. Deterioration was most marked when antiserum was stored lyophilised at room temperature. Storage of antiserum frozen confers no advantage over storage at 4°C provided precautions are taken to minimise bacterial contamination when storing antiserum in liquid form.

scholarly journals Impact of Storage Conditions on the Methanogenic Activity of Anaerobic Digestion Inocula

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1321 ◽  
Author(s):  
Sergi Astals ◽  
Konrad Koch ◽  
Sören Weinrich ◽  
Sasha D. Hafner ◽  
Stephan Tait ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Methanogenic Activity ◽  
Specific Methanogenic Activity ◽  
The Impact ◽  
And Storage ◽  
Over Time

The impact of storage temperature (4, 22 and 37 °C) and storage time (7, 14 and 21 days) on anaerobic digestion inocula was investigated through specific methanogenic activity assays. Experimental results showed that methanogenic activity decreased over time with storage, regardless of storage temperature. However, the rate at which the methanogenic activity decreased was two and five times slower at 4 °C than at 22 and 37 °C, respectively. The inoculum stored at 4 °C and room temperature (22 °C) maintained methanogenic activity close to that of fresh inoculum for 14 days (<10% difference). However, a storage temperature of 4 °C is preferred because of the slower decrease in activity with lengthier storage time. From this research, it was concluded that inoculum storage time should generally be kept to a minimum, but that storage at 4 °C could help maintain methanogenic activity for longer.

scholarly journals Post-harvest quality of bananas Prata-anã and Nanica after application of exogenous ethylene in maturation

2018 ◽  
Vol 40 (5) ◽  
Author(s):  
Regina Célia Gomes Garcia Nobre ◽  
Eliseu Marlônio Pereira de Lucena ◽  
Josivanda Palmeira Gomes ◽  
Dyalla Ribeiro de Araújo ◽  
Dannaya Julliethy Gomes Quirino
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Soluble Solids ◽  
Post Harvest ◽  
Peel Color ◽  
Exogenous Ethylene ◽  
And Storage

Abstract The objective of this study was to evaluate the post-harvest quality of bananas (Musa x paradisiaca L.) Prata-anã and Nanica after application of exogenous ethylene (C2H4) during maturation. Bananas of Prata-anã cultivar were harvested 18 weeks after the anthesis (WAA) and those of Nanica cultivar with 13 WAA. After harvest, the fruits were submitted to 0, 1, 2, 3, 4 and 5 applications of 15 mL of ethyl-5/m3 in refrigeration chambers at 15ºC and later stored at room temperature (24 to 28ºC) and refrigerated at 15°C for 10 days. Peel color, fresh weight loss, firmness, total soluble solids, total bark chlorophyll, total bark and pulp carotenoids were evaluated at 0, 3, 4, 7 and 10 days after harvest (DAH). The Assistat program was used in statistical analysis. Among the storage conditions, fruits kept under refrigeration had a longer shelf life. The Prata-anã cultivar was superior to Nanica, presenting maturation indexes ideal for transport and commercialization, evaluated for the interactions of storage temperature, ethylene (C2H4) applications and storage time. It was concluded that the banana Prata-anã requires 3 and Nanica 4 applications of ethyl, for the harvest with 18 and 13 weeks, respectively, in order to promote a fast and uniform maturation.

Incidence and Survival of Listeria monocytogenes in Ready-To-Eat Seafood Products

1997 ◽  
Vol 60 (4) ◽  
pp. 372-376 ◽  
Author(s):  
SUSAN A. MCCARTHY
Keyword(s):  
Listeria Monocytogenes ◽  
Storage Time ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Plate Count ◽  
Standard Plate Count ◽  
Smoked Salmon ◽  
Standard Plate ◽  
Seafood Products ◽  
Survival And Growth

The effects of processing and postprocess storage conditions on the incidence and survival of Listeria monocytogenes on crawfish (Procambaris sp.), crabmeat (Callinectus sapidus), and smoked salmon (Salmo salar) were evaluated. L. monocytogenes was recovered from 3% of whole boiled market crawfish samples and 17% of frozen vacuum-packaged partially cooked crawfish tail meat, but not from boiled crabmeat or smoked salmon. Contamination was most likely due to postprocess handling as commonly used methods of cooking (5 min boil or 20 min steep) reduced L. monocytogenes to nondetectable levels in laboratory-contaminated crawfish. In postprocess storage temperature abuse studies, cooked whole crawfish were inoculated internally and externally with 3.0 log CFU of L. monocytogenes per g and incubated at 22 or 30°C for 6 h. The greatest increase in numbers of cells, 1.9 log CFU/g (determined by standard plate count), occurred at 30°C on externally contaminated crawfish. There was little change in numbers of L. monocytogenes during cold storage (6°C, 5 days; −20°C, 15 days). There was little change in cell numbers associated with products stored at 22 or −20°C. At 6°C, numbers of cells associated with crabmeat increased by 3.8 log MPN/g after 6 days; however, there was no increase in numbers of cells associated with salmon. The results show that the survival and growth characteristics of L. monocytogenes are dependent on storage time and temperature and the nature of the seafood product.

Stability of Donepezil in an Extemporaneously Prepared Oral Liquid

2006 ◽  
Vol 19 (5) ◽  
pp. 282-285 ◽  
Author(s):  
Weeranuj Yamreudeewong ◽  
Eric Kurt Dolence ◽  
Deborah Pahl
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Storage Time ◽  
Microbial Growth ◽  
Storage Period ◽  
Significant Loss ◽  
Ambient Room Temperature ◽  
Oral Liquid ◽  
Liquid Preparation ◽  
The Stability

The stability of donepezil in an extemporaneously prepared oral liquid was studied. An aqueous liquid formulation of donepezil was prepared by reconstituting the powder from triturated 5-mg tablets with equal amounts of deionized water and 70% sorbitol solution with an expected donepezil concentration of 1 mg/mL. Polyethylene terephthalate plastic bottles containing donepezil liquid preparation were stored at ambient room temperature (22° C-26° C) and in the refrigerator (4° C-8° C). After a storage time of 1, 2, 3, and 4 weeks, donepezil liquid samples were analyzed in triplicate for donepezil concentrations by high-performance liquid chromatography. The concentrations of donepezil were found to be within the acceptable limit (± 10% of the initial concentration) in all test samples, which indicated that donepezil liquid preparation was stable at room temperature and in the refrigerator for up to 4 weeks. In addition, our study findings indicated that there was no microbial growth in the extemporaneously prepared donepezil liquid preparation after a storage period of 4 weeks in the refrigerator. In summary, the results of our study revealed that donepezil is stable (no significant loss of donepezil concentration and no microbial growth) in an extemporaneously prepared oral liquid when stored in the refrigerator for up to 4 weeks.

Effect of storage temperature on spore viability and early gametophyte development of three vulnerable species of Alsophila (Cyatheaceae)

2010 ◽  
Vol 58 (2) ◽  
pp. 89 ◽  
Author(s):  
Y. Li ◽  
Y. L. Zhang ◽  
C. D. Jiang ◽  
T. Wang ◽  
Q. Wang ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Storage Temperature ◽  
Vulnerable Species ◽  
Spore Viability ◽  
Great Loss ◽  
Gametophyte Development ◽  
Long Term Storage ◽  
Duration Of Storage

To effectively preserve the vulnerable species of Alsophila, we studied the effects of varying the temperature and duration of storage on spore viability, early gametophyte development and the microstructure of brown spores of three Alsophila species. Spores of A. spinulosa (Wall. ex Hook.) Tryon and A. gigantea Wall. ex Hook. lost viability quickly when stored at room temperature and suffered from great loss when stored at –18°C from 6 to 12 months. Within 1 month, spore viability of A. spinulosa and A. gigantea stored at 4°C was higher than that of those stored in liquid nitrogen. In contrast, long-term storage in liquid nitrogen resulted in a comparatively small loss of viability for these two species. The spores of A. podophylla Hook. died within 3 months after storage at room temperature, 4°C and –18°C, and they died within 12 months when stored in liquid nitrogen. The spores of A. spinulosa and A. gigantea stored at room temperature, 4°C and –18°C, were prone to develop into abnormal gametophytes. These results suggest that storage of A. spinulosa and A. gigantea spores in liquid nitrogen is an effective method of preserving these vulnerable species. The reasons for the failure to preserve ephemeral A. podophylla spores by storage in liquid nitrogen are discussed.

scholarly journals Chemical Variability in the Composition of Zhumeria majdae (Rech. F. & Wendelbo) Essential Oil According to Storage Time and Temperature

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 463
Author(s):  
Akbar Karami ◽  
Fatemeh Tashani ◽  
Aminallah Tahmasebi ◽  
Filippo Maggi
Keyword(s):  
Essential Oil ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Value ◽  
Oil Storage ◽  
Chemical Variability ◽  
Refrigerator Temperature ◽  
Storage Temperatures

Zhumeria majdae (Rech. F. & Wendelbo) is an aromatic herb belonging to the Lamiaceae family, traditionally employed in the Persian medicine for the treatment of a wide number of diseases. In the present study, the chemical composition of Z. majdae essential oil obtained from the plant’s aerial features, and stored at various temperatures (refrigerator temperature 4 °C, freezer temperature −20 °C, and room temperature 20 ± 3 °C) and times (0, 3, 6, and 9 months) was studied. The essential oil was isolated through hydrodistillation, and its composition was evaluated by gas chromatography/mass spectrometry (GC/MS). The results showed that the composition of essential oils changed as a function of the various storage temperatures and times. Linalool (34.85–48.45%), camphor (27.09–39.17%), limonene (1.97–4.88%), and camphene (1.6–4.84%) made up the main volatile compounds which showed differences in their concentrations according to the various storage conditions. Notably, when compared to a non-stored treatment sample (analyzed immediately after essential oil collection), the amount of linalool and camphor increased in all samples stored in all conditions of temperature and time, with the exception of the samples stored for nine months at room temperature. On the other hand, limonene and camphene contents decreased during the storage treatments, showing that the highest content of these compounds occurred in the non-stored treatment. Essential oil storage at the freezer temperature and for three months storage time resulted in the highest average value of the major constituents, highlighting these as the best conditions for obtaining the highest content of the major compounds.

Effects of Flavorings, Storage Conditions, and Storage Time on Survival of Staphylococcus aureus in Sürk Cheese

2005 ◽  
Vol 68 (7) ◽  
pp. 1487-1491 ◽  
Author(s):  
TUĞRUL M. MASATCIOĞLU ◽  
YAHYA K. AVŞAR
Keyword(s):  
Staphylococcus Aureus ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Conditions ◽  
Black Pepper ◽  
Ash Content ◽  
Mold Growth ◽  
Storage Duration ◽  
And Storage ◽  
Over Time

The objectives of this study were to determine the cumulative effects of flavorings (chili pepper, thyme, mint, cumin, nutmeg, allspice, clove, cinnamon, black pepper, salt, and hot red pepper paste), storage conditions, and storage time on the survival of Staphylococcus aureus in Sürk cheese and to monitor the associated chemical changes. Sürk cheese, a traditional Turkish cheese, was produced by heating diluted nonfat yogurt and adding flavorings to the resultant acid-heat curd. The cheese was later inoculated with S. aureus, shaped conically, and stored aerobically for mold growth and anaerobically in olive oil for 30 days at room temperature. The moisture content of aerobically stored cheese decreased over time and led to increases in total solids, salt, salt-in-moisture, and ash content during ripening (P &lt; 0.05). The presence or absence of the flavorings had no significant effect, whereas storage conditions and storage duration decreased the survival of S. aureus (P &lt; 0.05).

scholarly journals Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

Metabolites ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 203 ◽  
Author(s):  
Xinchen Wang ◽  
Haiwei Gu ◽  
Susana A. Palma-Duran ◽  
Andres Fierro ◽  
Paniz Jasbi ◽  
...  
Keyword(s):  
Large Scale ◽  
Storage Time ◽  
Storage Temperature ◽  
Urinary Metabolites ◽  
Storage Conditions ◽  
Inhibitory Effect ◽  
Urine Samples ◽  
C Storage ◽  
Liquid Chromatography Tandem Mass ◽  
The Stability

Human urine, which is rich in metabolites, provides valuable approaches for biomarker measurement. Maintaining the stability of metabolites in urine is critical for accurate and reliable research results and subsequent interpretation. In this study, the effect of storage temperature (4, 22, and 40 °C), storage time (24 and 48 h), and use of preservatives (boric acid (BA), thymol) and para-aminobenzoic acid (PABA) on urinary metabolites in the pooled urine samples from 20 participants was systematically investigated using large-scale targeted liquid chromatography tandem mass spectrometry (LC-MS/MS)-based metabolomics. Statistical analysis of 158 reliably detected metabolites showed that metabolites in urine with no preservative remained stable at 4 °C for 24 and 48 h as well as at 22 °C for 24 h, but significant metabolite differences were observed in urine stored at 22 °C for 48 h and at 40 °C. The mere addition of BA caused metabolite changes. Thymol was observed to be effective in maintaining metabolite stability in urine in all the conditions designed, most likely due to the inhibitory effect of thymol on urine microbiota. Our results provide valuable urine preservation guidance during sample storage, which is essential for obtaining reliable, accurate, and reproducible analytical results from urine samples.

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