scholarly journals Effect of Storage Temperature and Time on Stability of Liver Enzymes in Blood Serum

2020 ◽  
Vol 23 (5) ◽  
pp. 296-301
Author(s):  
Shadi Kolahdoozan ◽  
Sadaf G. Sepanlou ◽  
Maryam Sharafkhah ◽  
Elaheh Shaker ◽  
Ameneh Shayanrad ◽  
...  
Keyword(s):  
Linear Models ◽  
Liver Enzymes ◽  
Storage Temperature ◽  
Linear Regression Analysis ◽  
Storage Conditions ◽  
Prolonged Storage ◽  
Serum Samples ◽  
Long Term Storage ◽  
The Stability ◽  
Almost All

Background: It is increasingly common to collect and store specimens for future unspecified research. However, the effects of prolonged storage on the stability and quality of analytes in serum have not been well investigated. We aimed to determine whether the stability of liver enzymes extracted from frozen bio-samples stored at the baseline is affected by storage conditions. Methods: A total of four liver enzymes in the sera of 400 patients were examined following storage. After deter-mining the baseline measurements, the serum of each patient was aliquoted and stored at −70°C for three and six months, as well as one, two, and five years after collecting the original sample. The percent change from baseline measurements was calculated both statistically and clinically. Linear models were also used to correct the results of the samples based on the time they were frozen. Results: In almost all samples, liver enzymes were detectable until two years after the baseline, while in a signifi-cant proportion of samples, enzymes were not ultimately detectable five years after the baseline. Linear regression analysis on log-transformed levels of enzymes shows that the performance is acceptable until one year after the baseline. The performance of the prediction model declines substantially two and five years after the baseline, except for GGT. Conclusion: Long-term storage of serum samples significantly decreases the concentration of the liver enzymes from the baseline, except for GGT. It is not recommended to store samples for more than two years, as liver en-zymes are not detectable afterwards.

Stability of immunologic activity of human prostatic acid phosphatase in serum.

1982 ◽  
Vol 28 (5) ◽  
pp. 1163-1166 ◽  
Author(s):  
I W Chen ◽  
M I Sperling ◽  
H R Maxon ◽  
L A Kaplan
Keyword(s):  
Acid Phosphatase ◽  
Room Temperature ◽  
Chelating Agent ◽  
Prostatic Acid Phosphatase ◽  
Storage Conditions ◽  
Enzymic Activity ◽  
Serum Samples ◽  
Long Term Storage ◽  
The Stability ◽  
Immunologic Activity

Abstract The stability of the immunologic activity of human serum prostatic acid phosphatase (iPAP;EC 3.1.3.2) under various storage conditions was evaluated. Although more stable than the enzymic activity of serum PAP, serum iPAP was inactivated rapidly at room temperature at neutral and especially at alkaline pH. Purified iPAP in a phosphate buffer (pH 7.5) was stable for at least three days at room temperature but showed instability similar to that of serum iPAP when added to heat-treated serum (30 min at 56 degrees C, pH 8.3). Addition of a protease inhibitor, a sulfhydryl agent, or a chelating agent failed to preserve iPAP. Acidification of serum with an acetate buffer (5 mol/L, pH 5.0), 20 microliters/mL of serum, protected but could not restore serum iPAP activity. When stored at 24 degrees C, serum iPAP was most stable at pH 6.5. Acidification had little effect on PAP values by radioimmunoassay, iPAP values from acidified and unacidified serum samples being essentially the same. We recommend that blood samples drawn for PAP immunoassays be kept at 4 degrees C and that serum samples be separated and acidified as soon as practical. For long-term storage, acidified serum samples should be kept in small aliquots at -20 or -70 degrees C.

scholarly journals Investigation of stability of intrauterine aerosol preparation “Yodozol”

2018 ◽  
Vol 20 (92) ◽  
pp. 29-33
Author(s):  
R. M. Sachuk ◽  
O. A. Katsaraba
Keyword(s):  
Shelf Life ◽  
Medicinal Product ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Analgesic Effects ◽  
Aerosol Preparation ◽  
Long Term Storage ◽  
The Stability ◽  
Term Storage

For standardization, quality control, study of stability and establishment of storage conditions and terms of use, complex preclinical trials of the new development of PE “Biopharm” and the Experimental Station of Epizootology IVM NAAN – aerosol preparation “Yodozol” have been carried out. The methods of evaluation of a medicinal product applied to aerosols are used, which include: determination of changes in appearance, inspection of packaging for leakproofness, measurement of the percentage of contents of the package, the establishment of qualitative and quantitative indicators of active substances, and also the study of microbiological purity of the product. “Yodozol” is a light yellow liquid, 1 ml of which contains 5 mg of iodine and 10 mg of potassium iodide. The drug is used for the prevention and treatment of postnatal intrauterine infections in cows, pigs, sheep and goats (endometritis, pyrometers, cervicitis, vaginitis, delayed digestion caused by microorganisms sensitive to iodine), after obstetrics aid, cesarean section and postpartum sanitation of the uterus. The drug has antimicrobial, anti-inflammatory and analgesic effects, improves the proliferative processes of the genital organs, reduces the time for recovery of animals. The drug is used according to the guidelines, after its production livestock is used without restrictions. The shelf-life, which is the result of the test of the dasg according to the «stability» indicator, has been determined, which was performed under long-term storage in a place protected from light at a temperature range from + 5 ± 2 °С to + 25 ± 2 °С. The studies conducted after 6, 12, 24 and 30 months showed complete compliance of the quality indices with the declared standards when stored for 24 months in the temperature corridor from + 5 °C to + 20 °C. With an increase in storage temperature to + 25 °C or more, a slight quantitative decrease in the concentration of antimicrobial components occurred. In addition, with long-term storage of drugs, release of the contents from the cylinder became uneven and foam acquired a shade less than the saturation rate, increased microbiological contamination. Thus, according to the results of the study, the established shelf life of the preparation is 2 years at the recommended storage temperature from +5 to           +20 °С. All studies conducted on the stability of the aerosol intrauterine drug “Yodozol” were included in the registration materials of the medicinal product.

scholarly journals Aroma of mature-green and tree-ripe mangoes after refrigerated air or controlled atmosphere storage

2022 ◽  
Vol 52 (6) ◽  
Author(s):  
Renar João Bender ◽  
Jeffrey Karl Brecht ◽  
Elizabeth Amory Baldwin
Keyword(s):  
Storage Temperature ◽  
Storage Conditions ◽  
Controlled Atmosphere Storage ◽  
Controlled Atmospheres ◽  
Postharvest Handling ◽  
Terpene Synthesis ◽  
Almost All ◽  
Atmosphere Storage ◽  
Aroma Components ◽  
Green Stage

ABSTRACT: Mango flavor is dependent on cultivar characteristics and postharvest handling procedures. Mangoes harvested with the ripening metabolism initiated develop better flavor than mangoes harvested at the mature-green stage. Different cultivars were harvested at both ripeness stages and evaluated to determine the effect of fruit ripeness, storage temperature and atmosphere on the volatiles present in aroma profiles. Mangoes of the cultivars Haden, Keitt and Tommy Atkins at distinct ripeness stages were stored in controlled atmospheres (CA) with 2, 5 or 21 kPa O2 plus 0, 10 or 25 kPa CO2 at 5, 8, 12 or 15 °C. Terpene concentrations of mangoes stored in air were higher than the concentrations in mangoes stored in CA. The sesquiterpene α-copaene did not present recognizable peaks in almost all elusion sequences. The same result was observed with the monoterpene β-pinene in cv. Haden and cv. Keitt mangoes while in ‘Tommy Atkins’ fruit β-pinene concentrations were below 1.06 µL.L-1. Ethanol and acetaldehyde concentrations were significantly higher in mangoes from 2 kPa O2 storage than those from air storage or the other CA treatments. Terpene synthesis in air or CA storage in all cultivars varied significantly, preventing generalizations as to what storage conditions favor or limit aroma components elution.

scholarly journals Effect of storage temperature on Streptococcus mutans viability

2018 ◽  
Vol 47 (2) ◽  
pp. 74-78
Author(s):  
Ana Lídia Soares COTA ◽  
Ronaldo Gomes ALVIM
Keyword(s):  
Streptococcus Mutans ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Descriptive Statistics ◽  
Bacterial Isolates ◽  
Future Studies ◽  
Long Period ◽  
Different Temperatures ◽  
Almost All ◽  
Microbiological Research

Abstract Introduction Proper storage conditions and maintenance of viable biological material plays an important role in microbiological research, allowing for the opportunity to conduct future studies. Objective To evaluate the viability of Streptococcus mutans strains that were previously grown and stored under different temperatures for approximately eight years. Material and method In this study, we evaluated 393 bacterial isolates that were stored in a freezer at -80°C (G1) and 200 isolates stored in a freezer at -20°C (G2). Aliquots of each sample were plated on blood agar and mitis-salivarius bacitracin sucrose agar-solidified medium. After incubating under microaerophilic conditions in an incubator at 37°C for 72 hours, the presence, morphology and purity of bacterial growth was observed. The data were analyzed by means of descriptive statistics. Result Microbial viability was observed in almost all samples (99.7%) in G1, whereas all isolates stored at -20°C were considered inviable. Conclusion The viability of S. mutans is influenced by the storage temperature of the samples, and the strains remain viable when stored under ideal temperature conditions (-80°C), even when stored for a long period of time.

scholarly journals The Influence of Serum Sample Storage Conditions on Selected Laboratory Parameters Related to Oxidative Stress: A Preliminary Study

Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Lilla Pawlik-Sobecka ◽  
Katarzyna Sołkiewicz ◽  
Izabela Kokot ◽  
Aleksandra Kiraga ◽  
Sylwia Płaczkowska ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Serum Sample ◽  
Storage Conditions ◽  
Wilcoxon Test ◽  
Reference Ranges ◽  
Sample Storage ◽  
Serum Samples ◽  
The Stability ◽  
The Individual ◽  
The Impact

The present work aims at accessing the stability of biological material stored for diagnostic and scientific purposes. The influence of the temperature, storage time, and cyclic thawing on concentration stability of selected oxidative stress parameters in human serum was investigated. The study group consisted of 20 serum samples collected from healthy volunteers aged 18–52. The parameters whose reference ranges were not determined and to which validated determination methods did not correspond were examined by manual methods (FRAP and AOPP). Automatic methods were used to determine routine laboratory tests (albumin, total protein, bilirubin, uric acid) using the Konelab 20i® analyzer. The samples were stored at various temperatures (room temperature, 4 °C, −20 °C, −80 °C) for max 6 months and were subjected to cyclic thawing at 1 month intervals. In order to check whether any differences between the concentrations of the studied parameters existed when the samples were stored in various conditions, the paired Student t-test or Wilcoxon test and comparison to desirable bias were applied. Based on the obtained results, it was found that the temperature and time of serum sample storage significantly affected the stability of the analyzed parameters and determined different shelf lives of serum samples for oxidative stress examination. Therefore, continuing the investigation concerning the impact of storage conditions on various serum parameters seems justified due to the discrepancy between the individual results obtained by different researchers and the inconsistencies between the results of scientific research and the applicable recommendations.

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

2015 ◽  
Vol 16 (3) ◽  
pp. 620-627 ◽  
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.

scholarly journals Stability of Folate and Vitamin B12in Human Serum after Long-Term Storage: A Follow-Up after 13 Years

2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
Eugène H. J. M. Jansen ◽  
Piet K. Beekhof
Keyword(s):  
Human Serum ◽  
Storage Time ◽  
Vitamin B ◽  
Serum Samples ◽  
Long Term Storage ◽  
Nutrition Research ◽  
The Stability ◽  
Term Storage

In epidemiological and nutrition research, it is very important to evaluate the stability of biomarkers as function of both storage time and temperature. In this study, the stability of folate and vitamin B12in human serum samples has been tested after long-term storage at −80°C up to 13 years. Serum samples of 16 individuals were used in this study. The concentration of folate and vitamin B12has been determined att=0and at 1, 8, and 13 years after storage at −80°C. The folate concentrations in serum samples remained stable at −80°C. The concentration of vitamin B12was decreasing during the time of the study to about 50%. The correlation of the folate and also of the vitamin B12concentrations in the stored samples compared with the starting values was still good. Therefore, although the concentration of vitamin B12decreased upon storage, reliable comparative analyses can still be performed.

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

scholarly journals Evaluation of the Influence of a Hydrogel Containing AMPD on the Stability of Tetracycline Hydrochloride

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1381
Author(s):  
Agnieszka Kostrzębska ◽  
Adrianna Złocińska ◽  
Witold Musiał
Keyword(s):  
Aqueous Solution ◽  
Fatty Acids ◽  
Antimicrobial Activity ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Tetracycline Hydrochloride ◽  
Dual Action ◽  
Hydrogel Formulation ◽  
The Stability ◽  
High Instability

Tetracyclines, as beneficial antimicrobial factors in both local and systemic therapy, are characterized by high instability. The aim of the study was the development of the influence of hydrogel formulation on the tetracycline hydrochloride (TC) level under varying storage conditions. The HPLC, XPRD as well as SEM and macroscopic observations were involved in the study. The TC concentration decreased within ca. two months from 9.37 µg/mL to 4.41 µg/mL in the case of the photoprotected TC solution stored at 23 °C, whereas the decrease in storage temperature did not improve the final level of TC. In the presence of AMPD, the TC level in aqueous solution decreased drastically to ca. 1 µg/mL. Application of a polyacrylic acid derivative enabled conservation of the TC level through the ca. two months. Thus, the use of alcoholamine in the preparation of the TC hydrogel may result in the development of a therapeutic product with a dual action against acne, including antimicrobial activity and saponification of free fatty acids deposited in the follicles.

scholarly journals Expired Probiotics: What is Really in Your Cabinet?

2020 ◽  
Author(s):  
Hannah Wilcox ◽  
Charles Carr ◽  
Shannon Seney ◽  
Gregor Reid ◽  
Jeremy Burton
Keyword(s):  
Storage Conditions ◽  
Rrna Gene ◽  
Expiry Date ◽  
Product Formulation ◽  
Long Term Storage ◽  
Original Product ◽  
Expiration Time ◽  
Rrna Gene Sequencing ◽  
The Stability

Abstract Background: The popularity of using probiotics has surged, since they became widely accepted as safe and help improve general health. Inevitably, some of these products are used after expiration when microbial cell viability is below the recommended effective dose. Given that probiotics are live microorganisms administered in adequate amounts, the aim of this study was to measure viability in expired products and assess how packaging and storage conditions impact efficacy, if at all.Results: Thirty-three expired probiotic products were evaluated, of which 26 were stored in conditions recommended by the manufacturer. The viable microbial counts were enumerated and representative isolates identified by 16S and ITS rRNA gene sequencing. While the products had a mean past expiration time of 11.32 (1 to 22) years, 22 still had viable contents, and 5 were within or above the original product cell count claim. Product formulation, and number of species present did not appear to impact the stability of the products. However, overall packaging type, storage conditions and time since expiry were found to affect viability. All products with viable cells had the strain stipulated on the label.Conclusion: Despite some selected probiotic products retaining viability long past their expiry date (indicating long term storage is possible), the total counts were mostly well below that required for efficacious use as recommended by the manufacturer. Consuming expired probiotics may not yield the benefits for which they were designed.

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