Factors affecting the accuracy and reliability of the measurement of anti-Müllerian hormone concentration in the clinic

Objective We aimed to identify the factors that influence serum anti-Müllerian hormone (AMH) concentration measurements. Methods We collected serum samples between May and September 2018 and compared the effect on AMH concentration measured by ELISA of conditions including venepuncture, storage time, storage temperature, locations of the reaction microplate, and the use of the oral contraceptive pill and gonadotrophin-releasing hormone (GnRH). Results AMH concentration was not affected by food intake but was affected by haemolysis. It was also much higher in samples on the edge of the ELISA microtitre plate. AMH concentration increased after incubation at room temperature for 1 day, 4°C for 3 days, −20°C for 1 month and −40°C for 4 months, but no change occurred during storage at −80°C for 9 months. AMH concentration was high in patients following GnRH agonist treatment but was not affected by oral contraceptives. Conclusions No fasting is required prior to AMH measurement. Placement of serum samples on the edge of microtitre plates affects the results of the AMH ELISA. If serum samples cannot be assayed immediately, it is best to store them at −80°C. Basal AMH concentration cannot be used as a measure of ovarian reserve after GnRH agonist treatment.

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Influence of storage time and temperature on the activity of urease

Bulgarian Chemical Communications ◽

10.34049/bcc.51.2.4536 ◽

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

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Formulation of Buprenorphine for Sublingual Use in Neonates

The Journal of Pediatric Pharmacology and Therapeutics ◽

10.5863/1551-6776-16.4.281 ◽

2011 ◽

Vol 16 (4) ◽

pp. 281-284 ◽

Cited By ~ 1

Author(s):

Ellena A. Anagnostis ◽

Rania E. Sadaka ◽

Linda A. Sailor ◽

David E. Moody ◽

Kevin C. Dysart ◽

...

Keyword(s):

Room Temperature ◽

Storage Time ◽

Storage Temperature ◽

Sublingual Administration ◽

Tandem Mass ◽

Abstinence Syndrome ◽

Length Of Treatment ◽

The Mean ◽

The Stability ◽

Length Of Hospitalization

OBJECTIVES The only medication used sublingually in the neonate is buprenorphine for the treatment of neonatal abstinence syndrome (NAS). Compared with morphine, buprenorphine reduces the length of treatment and length of hospitalization in neonates treated for NAS. The objective of this study was to characterize the stability of ethanolic buprenorphine for sublingual administration. METHODS Buprenorphine solution was prepared and stored in amber glass source bottles at either 68°F to 77°F (20°C-25°C) or 36°F to 46°F (2.2°C-7.8°C). Samples were collected from each of these batches on days 0, 3, 7, 14, and 30. Additional samples were withdrawn at baseline from each batch and placed in oral dispensing syringes for 3 and 7 days. Buprenorphine concentration was assessed by liquid chromatography–electrospray ionization–tandem mass spectrometry. RESULTS Neither storage temperature (p=0.65) nor storage time (p=0.24) significantly affected buprenorphine concentrations. All of the mean concentrations, regardless of storage temperature, were above 95% of the labeled concentration, and the potency was maintained for samples stored either in the original amber glass source bottles or in oral syringes. CONCLUSIONS An ethanolic buprenorphine solution is stable at room temperature for 30 days.

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Factors Affecting Patulin Production by Penicillium expansum†

Journal of Food Protection ◽

10.4315/0362-028x-65.12.1937 ◽

2002 ◽

Vol 65 (12) ◽

pp. 1937-1942 ◽

Cited By ~ 65

Author(s):

J. L. McCALLUM ◽

R. TSAO ◽

T. ZHOU

Keyword(s):

Room Temperature ◽

Storage Temperature ◽

Fungal Growth ◽

Penicillium Expansum ◽

Teratogenic Effects ◽

Factors Affecting ◽

Capillary Electrophoresis Method ◽

Electrophoresis Method ◽

Penicillium Spp ◽

Mycelial Development

Patulin, a mycotoxin produced by Penicillium spp. during fruit spoilage, is a major concern with regard to human health because exposure can result in severe acute and chronic toxicity, including carcinogenic, mutagenic, and teratogenic effects. In this study, we investigated the effects of Penicillium expansum isolate, apple cultivar, storage temperature and time, and pH on the production of patulin. Patulin was analyzed by a previously developed micellar electrokinetic capillary electrophoresis method. P. expansum isolates originating from across Ontario produced widely differing levels of patulin, ranging from 0 to >6 mg/g by dry mycelial weight. The highest patulin levels were those for isolates displaying aggressive growth (characterized by rapidly increasing acidity) accompanied by profuse mycelial development. Distinct patterns in fungal growth rates and patulin production were evident among isolates grown in McIntosh, Empire, and Mutsu ciders. Extensive fungal growth and higher patulin levels (538 to 1,822 μg/ml on day 14) in apple ciders were associated with incubation at room temperature (25°C), although potentially toxic patulin levels (75 to 396 μg/ml on day 24) were also found in refrigerated ciders (4°C) inoculated with P. expansum.

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Diagnosis of soil-transmitted helminths using the Kato-Katz technique: What is the influence of stirring, storage time and storage temperature on stool sample egg counts?

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009032 ◽

2021 ◽

Vol 15 (1) ◽

pp. e0009032

Author(s):

Felix Bosch ◽

Marta S. Palmeirim ◽

Said M. Ali ◽

Shaali M. Ame ◽

Jan Hattendorf ◽

...

Keyword(s):

Stool Sample ◽

Room Temperature ◽

Storage Time ◽

Storage Temperature ◽

Negative Impact ◽

The Other ◽

Time Points ◽

Soil Transmitted Helminths ◽

Slide Preparation ◽

Stool Samples

Background Soil-transmitted helminths infect about one fifth of the world’s population and have a negative impact on health. The Kato-Katz technique is the recommended method to detect soil-transmitted helminth eggs in stool samples, particularly in programmatic settings. However, some questions in its procedure remain. Our study aimed to investigate the effect of storage time, storage temperature and stirring of stool samples on fecal egg counts (FECs). Methodology/Principal findings In the framework of a clinical trial on Pemba Island, United Republic of Tanzania, 488 stool samples were collected from schoolchildren. These samples were evaluated in three experiments. In the first experiment (n = 92), two Kato-Katz slides were prepared from the same stool sample, one was stored at room temperature, the other in a refrigerator for 50 hours, and each slide was analyzed at nine time points (20, 50, 80, 110, 140 minutes, 18, 26, 42 and 50 hours). In the second experiment (n = 340), whole stool samples were split into two, one part was stored at room temperature, and the other part was put in a refrigerator for 48 hours. From each part one Kato-Katz slide was prepared and analyzed at three time points over two days (0, 24 and 48 hours). In the third experiment (n = 56), whole stool samples where stirred for 15 seconds six times and at each time point a Kato-Katz slide was prepared and analyzed. Mean hookworm FECs of Kato-Katz slides stored at room temperature steadily decreased following slide preparation. After two hours, mean hookworm FECs decreased from 22 to 16, whereas no reduction was observed if Kato-Katz slides were stored in the refrigerator (19 vs 21). The time x storage interaction effect was statistically significant (coefficient 0.26, 95% CI: 0.17 to 0.35, p < 0.0001). After 24 hours mean hookworm FECs dropped close to zero, irrespective of the storage condition. Whole stool samples stored at room temperature for one day resulted in a mean hookworm FEC decrease of 23% (p < 0.0001), compared to a 13% reduction (p < 0.0001) if samples were stored in the refrigerator. Fecal egg counts of A. lumbricoides and T. trichiura remained stable over time regardless of storage temperature of whole stool samples. Finally, we found a significant reduction of the variation of hookworm and T. trichiura eggs with increasing rounds of stirring the sample, but not for A. lumbricoides. For hookworm we observed a simultaneous decrease in mean FECs, making it difficult to draw recommendations on stirring samples. Conclusions/Significance Our findings suggest that stool samples (i) should be analyzed on the day of collection and (ii) should be analyzed between 20–30 minutes after slide preparation; if that is not possible, Kato-Katz slides can be stored in a refrigerator for a maximum of 110 minutes.

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Effect of Storage Time and Temperature on Fresh Unprocessed Cord Blood.

Blood ◽

10.1182/blood.v106.11.5272.5272 ◽

2005 ◽

Vol 106 (11) ◽

pp. 5272-5272

Author(s):

Marcus R. Vowels ◽

Jessica Stylianou ◽

Leigh Mison

Keyword(s):

Cord Blood ◽

Room Temperature ◽

Storage Time ◽

Storage Temperature ◽

Haematopoietic Stem Cell ◽

Optimal Conditions ◽

Cd34 Cells ◽

Different Temperatures ◽

Thawing Process ◽

Temperature Ranges

Abstract Studies on the optimal conditions to store fresh cord blood (CB) in order to optimise haematopoietic stem cell (HSC) recovery prior to processing and cryopreservation have produced conflicting data. In this study we investigate the effects of time and temperature on CB HSC after collection. We also investigate whether the process of cryopreservation and thawing aggravates stress created by storage prior to cryopreservation. 30 CB units were collected and transported to the laboratory within 5 hours of collection. An aliquot of each CB unit was tested for nucleated cell count (NCC), CD34 count, CD34 viability and CFU-GEMM, and then frozen with 10% DMSO. Each CB unit was then separated into three 10 ml portions and incubated at 3 different temperatures (4–8°C, 21–24°C and 29–31°C). After 24, 36 or 48 hours, samples were taken and tested. An aliquot of each of the portions was then cryopreserved. After a minimum of 1 week, the cryopreserved samples were thawed and tested. For fresh samples incubated for 24 hrs or 36 hrs there was no difference over time when CB was incubated at 4–8°C, whereas, at temperatures above 20°C, there was either a trend or significant decrease in CD34 and CFU colonies with time. For thawed samples, viable CD34 and CFU colonies were decreased below baseline at either one or both 24 hr and 36 hr time points. This was particularly apparent for CFU colony measurements for samples kept at 29–31°C. At 48 hrs, at each of the temperature ranges (4–8°C, 21–24°C and 29–31°C), CFU were significantly lower for fresh (21.1, 16.8 and 14.0; baseline 31.0) and thawed (9.3, 8.5 and 3.0; baseline 2.7) samples and viable CD34 were significantly lower for thawed (2.0, 2.46 and 1.8; baseline 2.7) samples respectively (p<0.001). In conclusion, the best survival /recovery was seen with CB stored at 4–8° C and for ≥ 36 hrs. Temperatures above room temperature (21–24°C) appeared detrimental. The data also indicate that this damage becomes more evident when tested after the CB has gone through the cryopreservation and thawing process, and is even more evident the higher the temperature and the greater the time of storage prior to cryopreservation. These results have implications for quality and safety of CB stored for clinical use. Viable CD34 and CFU related to incubation time and temperature, tested pre- and post-cryopreservation. Viable CD34 cells x 10e6 CFU-GEMM /12,500 cells plated Storage temperature 4–8C° 21–24°C 29–31°C 4–8°C 21–24°C 29–31°C Baseline 3.4 3.4 3.4 20.9 20.9 20.9 Fresh 24 hrs 3.3 3.67 2.45 20.4 18.8 21.6 36 hrs 3.7 2.45 2.74 20.5 19.6 17.4 Frozen / Baseline 3.0 3.0 3.0 11.0 11.0 11.0 Thawed 24 hrs 2.7 2.8 2.5 11.8 11.8 6.1 36 hrs 2.5 2.84 2.1 10.6 10.1 4.7

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Factors affecting stability of plasma brain-derived neurotrophic factor

Scientific Reports ◽

10.1038/s41598-020-77046-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jocelyn M. Wessels ◽

Ravi K. Agarwal ◽

Aamer Somani ◽

Chris P. Verschoor ◽

Sanjay K. Agarwal ◽

...

Keyword(s):

Neurotrophic Factor ◽

Storage Time ◽

Storage Temperature ◽

Plasma Concentrations ◽

Brain Derived Neurotrophic Factor ◽

Plasma Samples ◽

Factors Affecting ◽

Freeze Thaw ◽

Gynecological Disorders ◽

Acceptable Range

AbstractCirculating concentrations of brain-derived neurotrophic factor (BDNF) have been linked to cancer, neuropsychiatric, diabetes, and gynecological disorders. However, factors influencing plasma storage and subsequent BDNF quantification are incompletely understood. Therefore, the anticoagulant used in plasma separator tubes, storage-time, storage-temperature, and repeated freeze–thaw cycles on circulating BDNF concentrations was evaluated. Peripheral blood samples were collected from healthy women (n = 14) and men (n = 10) recruited prospectively from McMaster University (August 2014). Blood was collected from the cubital vein into plasma separator tubes containing five different anticoagulant systems [K2EDTA, Li-Hep, Li-Hep (gel), Na-Hep, Na-Hep (glass)], and placed on ice for transport to the lab for centrifugation. Plasma samples (n = 16) collected in K2EDTA tubes from women recruited to a previous study (April 2011 to December 2012) were used to determine the effect of multiple freeze–thaw cycles. Plasma BDNF was quantified using a commercially available ELISA kit. Plasma concentrations of BDNF were significantly affected by the type of plasma separator tube, storage-time, and number of freeze–thaw cycles. Storage temperature (− 20 vs. − 80 °C) did not significantly affect the quantity of BDNF measured as mean BDNF concentrations generally fell within our calculated acceptable change limit up to 6 months in the freezer. Our results suggest that for quantification of circulating BDNF blood collected in K2EDTA tubes and plasma stored up to 6 months at either − 20 or − 80 °C produces reproducible results that fall within an acceptable range. However, plasma samples stored beyond 6 months and repeated freeze–thaw cycles should be avoided.

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Improving IBD diagnosis and monitoring by understanding preanalytical, analytical and biological fecal calprotectin variability

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2018-0134 ◽

2018 ◽

Vol 56 (11) ◽

pp. 1926-1935 ◽

Cited By ~ 15

Author(s):

Andrea Padoan ◽

Renata D’Incà ◽

Maria Luisa Scapellato ◽

Rudi De Bastiani ◽

Roberta Caccaro ◽

...

Keyword(s):

Room Temperature ◽

Storage Time ◽

Storage Temperature ◽

Clinical Effectiveness ◽

Fecal Calprotectin ◽

Time Interval ◽

Biological Variability ◽

Reference Change Value ◽

The Difference ◽

Clinically Significant

Abstract Background: The appropriate clinical use of fecal calprotectin (fCal) might be compromised by incomplete harmonization between assays and within- and between-subjects variability. Our aim was to investigate the analytical and biological variability of fCal in order to provide tools for interpreting fCal in the clinical setting. Methods: Experiments were conducted to investigate the effects of temperature and storage time on fCal. Thirty-nine controls were enrolled to verify biological variability, and a case-control study was conducted on 134 controls and 110 IBD patients to compare the clinical effectiveness of three different fCal assays: ELISA, CLIA and turbidimetry. Results: A 12% decline in fCal levels was observed within 24 h following stool collection irrespective of storage temperature. Samples were unstable following a longer storage time interval at room temperature. Within- and between-subjects fCal biological variability, at 31% and 72% respectively, resulted in a reference change value (RCV) in the region of 100%. fCal sensitivity in distinguishing between controls and IBD patients is satisfactory (68%), and the specificity high (93%) among young (<65 years), but not among older (≥65 years) subjects (ROC area: 0.584; 95% CI: 0.399–0.769). Among the young, assays have different optimal thresholds (120 μg/g for ELISA, 50 μg/g for CLIA and 100 μg/g for turbidimetry). Conclusions: We recommend a standardized preanalytical protocol for fCal, avoiding storage at room temperature for more than 24 h. Different cutoffs are recommended for different fCal assays. In monitoring, the difference between two consecutive measurements appears clinically significant when higher than 100%, the fCal biological variability-derived RCV.

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Chlorophyll Determination in Green Pepper Using two Different Extraction Methods

Current Research in Nutrition and Food Science Journal ◽

10.12944/crnfsj.4.special-issue1.05 ◽

2015 ◽

Vol 4 (1) ◽

pp. 52-60 ◽

Cited By ~ 4

Author(s):

E Manolopoulou ◽

Th Varzakas ◽

A Petsalaki

Keyword(s):

Chlorophyll Content ◽

Storage Time ◽

Storage Temperature ◽

Extraction Methods ◽

Green Pepper ◽

Factors Affecting ◽

Chlorophyll Contents ◽

Chlorophyll Extraction ◽

And Storage

The aim of this paper is the comparison of the classic Arnon method with the DMSO method regarding the determination of chlorophyll content in California Wonder peppers stored for 25 days at 5, 10 and 20°C. The results suggest that the factors affecting chlorophyll degradation are temperature and storage time, as well as their interaction. There is a linear relationship between changes in chlorophyll content and storage temperature. The statistical analysis indicates that the two chlorophyll extraction methods considerably differ, as the chlorophyll contents obtained through the Arnon method were, in all cases, lower than those obtained through DMSO. It has to be stressed that the results greatly depend on both the selected solvent and the chlorophyll extraction method.

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The Changes Of Characteristic Fermented Milk During Room Temperature Storage

Jurnal Ilmu dan Teknologi Pangan (ITEPA) ◽

10.24843/itepa.2021.v10.i01.p11 ◽

2021 ◽

Vol 10 (1) ◽

pp. 119

Author(s):

Hidayanti Sukmaningrum ◽

Luh Putu Trisna Darmayanti ◽

Gusti Ayu Kadek Diah Puspawati

Keyword(s):

Sensory Evaluation ◽

Room Temperature ◽

Storage Time ◽

Storage Temperature ◽

Fermented Milk ◽

Milk Product ◽

Total Acid ◽

Room Temperature Storage ◽

Acid Ph ◽

Temperature Storage

Fermented milk is a functional food has beneficial to human health. The recommended concentration of probiotic bacteria to provide health benefits is 106-108 CFU/ml of product. The storage temperature is one of the factor that affected the characteristics of fermented milk. This research was conducted to determine the effect of storage time at room temperature to the characteristics of fermented milk product and determine the length of maximum storage at room temperature. The research design was Completely Randomized Design with storage time treatment at room temperature for 0, 2, 4, 6, 8, 10, 12, and 14 days. Each treatment was repeated 2 times so that 16 experimental units were obtainned. The variables that were observed included total LAB, total acid, pH, and sensory evaluation (aroma, taste, and overall acceptance). Data were analyzed with analysis of variance, if the treatment had an effect on the variables then followed by Duncan multiple range Test. The results showed that the treatment of fermented milk in room temperature storage significantly affected the total acid, pH, total LAB, and sensory evaluation (aroma, taste, and overall acceptance). The maximum storage of the room temperature was days with total acid of 0.5%, pH 3.63, total LAB 7.71 log cfu/ml or 5.12 x 107 cfu/ml, the sensory of aroma, taste, and overall acceptance was liked.

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Monostearin effects on the formation of precipitate in palm oil biodiesel and petroleum diesel blends with various storage temperature

E3S Web of Conferences ◽

10.1051/e3sconf/20185200026 ◽

2018 ◽

Vol 52 ◽

pp. 00026 ◽

Cited By ~ 1

Author(s):

Mohamad Aufar Ghaizani ◽

Imam Abdurrosyid ◽

Imam Paryanto ◽

Misri Gozan

Keyword(s):

Low Temperature ◽

Palm Oil ◽

Room Temperature ◽

Storage Time ◽

Storage Temperature ◽

Biodiesel Production ◽

Blend Ratio ◽

Early Results ◽

Biodiesel Blend ◽

Palm Oil Biodiesel

Biodiesel is one of the renewable energy forms that is on demand in Indonesia. In the biodiesel production process, impurities such as Saturated Monoglycerides (SMG) in the form of monostearin that precipitate at low temperature are commonly formed. This is caused by high Final Melting Temperature (FMT) of SMG. Formation of solid deposits when it reaches a temperature above Cloud Point (CP) is then unavoidable under these conditions. The use of palm oil biodiesel and petroleum diesel blends (BXX) with biodiesel blend ratio of 10% (B10), 20% (B20) and 30% (B30) accelerates precipation process which renders clogging on fuel filters. These works examined the effect monostearin content and temperature on the precipitation rate. Investigation is carried out at 15°C, 20°C, 25°C, and room temperature (30-33°C) with varying content of monostearin (0.4%, 0.7%, and 0.9%). Early results show that for 0.4% monostearin content in 100 ml B20, the amount of precipitate formed at temperature 15 oC was 31.3 mg. This value was higher than that at room temperature (6.3 mg) after 2 weeks storage time. This value was higher compared to B20 (21.5 mg). This indicates that as the biodiesel ratio in BXX become higher, the amount of FAME will increase which effect monostearin solubility in BXX at low temperature.

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