scholarly journals Reproducibility and Accuracy of Measurements of Free and Total Prostate-Specific Antigen in Serum vs Plasma after Long-Term Storage at −20 °C

2006 ◽  
Vol 52 (2) ◽  
pp. 235-239 ◽  
Author(s):  
David Ulmert ◽  
Charlotte Becker ◽  
Jan-Åke Nilsson ◽  
Timo Piironen ◽  
Thomas Björk ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Population Based ◽  
Plasma Samples ◽  
Long Term Storage ◽  
Edta Plasma ◽  
Random Variability ◽  
Term Storage

Abstract Background: Long-term frozen storage may alter the results of prostate-specific antigen (PSA) measurements, mainly because of degradation of free PSA (fPSA) in vitro. We compared the effects of long-term storage on fPSA, total PSA (tPSA), and complexed PSA (cPSA) in serum vs EDTA-plasma samples. Methods: We measured fPSA and tPSA concentrations in matched pairs of archival serum and EDTA-plasma samples (stored frozen at −20 °C for 20 years) from a large population-based cohort in Malmö, Sweden. We also compared concentrations in age-matched men with those in samples not subjected to long-term storage, obtained from participants in a population-based study of prostate cancer screening in Göteborg, Sweden. These contemporary samples were handled according to standardized preanalytical and analytical protocols aimed at minimizing in vitro degradation. tPSA and fPSA measurements were performed with a commercial assay (Prostatus Dual Assay; Perkin-Elmer Life Sciences). Results: Concentrations of tPSA and fPSA and calculated cPSA (tPSA − fPSA) in archival plasma were not significantly different from those in contemporary serum from age-matched men. In archival serum, however, random variability of fPSA was higher vs plasma than in contemporary samples, whereas systematic error of fPSA analyses was similarly small in archival and contemporary serum and plasma. Conclusions: Concentrations of tPSA and calculated cPSA were highly stable in plasma and serum samples subjected to long-term storage at −20 °C. Greater random variability, rather than a systematic decrease, may explain differences in fPSA analyses observed in archival serum.

Total Prostate Specific Antigen Stability Confirmed After Long-Term Storage of Serum at −80C

2008 ◽  
Vol 180 (2) ◽  
pp. 534-538 ◽  
Author(s):  
Amanda Beth Reed ◽  
Donna Pauler Ankerst ◽  
Robin J. Leach ◽  
Gilbert Vipraio ◽  
Ian M. Thompson ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Long Term Storage ◽  
Total Prostate Specific Antigen ◽  
Term Storage

scholarly journals Effects of Long-Term Storage at −80 °C on the Human Plasma Metabolome

Metabolites ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 99 ◽  
Author(s):  
Antje Wagner-Golbs ◽  
Sebastian Neuber ◽  
Beate Kamlage ◽  
Nicole Christiansen ◽  
Bianca Bethan ◽  
...  
Keyword(s):  
Human Plasma ◽  
Ethylenediaminetetraacetic Acid ◽  
Plasma Metabolites ◽  
Prolonged Storage ◽  
Plasma Samples ◽  
Long Term Storage ◽  
Plasma Metabolome ◽  
Edta Plasma ◽  
Term Storage

High-quality biological samples are required for the favorable outcome of research studies, and valid data sets are crucial for successful biomarker identification. Prolonged storage of biospecimens may have an artificial effect on compound levels. In order to investigate the potential effects of long-term storage on the metabolome, human ethylenediaminetetraacetic acid (EDTA) plasma samples stored for up to 16 years were analyzed by gas and liquid chromatography-tandem mass spectrometry-based metabolomics. Only 2% of 231 tested plasma metabolites were altered in the first seven years of storage. However, upon longer storage periods of up to 16 years and more time differences of few years significantly affected up to 26% of the investigated metabolites when analyzed within subject age groups. Ontology classes that were most affected included complex lipids, fatty acids, energy metabolism molecules, and amino acids. In conclusion, the human plasma metabolome is adequately stable to long-term storage at −80 °C for up to seven years but significant changes occur upon longer storage. However, other biospecimens may display different sensitivities to long-term storage. Therefore, in retrospective studies on EDTA plasma samples, analysis is best performed within the first seven years of storage.

scholarly journals HMGB1 concentration measurements in trauma patients: assessment of pre-analytical conditions and sample material

2019 ◽  
Vol 26 (1) ◽  
Author(s):  
William Ottestad ◽  
Ingrid N. Rognes ◽  
Erlend Skaga ◽  
Cassandra Frisvoll ◽  
Guttorm Haraldsen ◽  
...  
Keyword(s):  
Western Blot ◽  
Room Temperature ◽  
Trauma Patients ◽  
Plasma Samples ◽  
Sample Material ◽  
Limits Of Agreement ◽  
Freeze Thaw ◽  
Long Term Storage ◽  
Term Storage

Abstract Background HMGB1 is a mediator of systemic inflammation in sepsis and trauma, and a promising biomarker in many diseases. There is currently no standard operating procedure for pre-analytical handling of HMGB1 samples, despite that pre-analytical conditions account for a substantial part of the overall error rate in laboratory testing. We hypothesized that the considerable variations in reported HMGB1 concentrations and kinetics in trauma patients could be partly explained by differences in pre-analytical conditions and choice of sample material. Methods Trauma patients (n = 21) admitted to a Norwegian Level I trauma center were prospectively included. Blood was drawn in K2EDTA coated tubes and serum tubes. The effects of delayed centrifugation were evaluated in samples stored at room temperature for 15 min, 3, 6, 12, and 24 h respectively. Plasma samples subjected to long-term storage in − 80 °C and to repeated freeze/thaw cycles were compared with previously analyzed samples. HMGB1 concentrations in simultaneously acquired arterial and venous samples were also compared. HMGB1 was assessed by standard ELISA technique, additionally we investigated the suitability of western blot in both serum and plasma samples. Results Arterial HMGB1 concentrations were consistently lower than venous concentrations in simultaneously obtained samples (arterial = 0.60 x venous; 95% CI 0.30–0.90). Concentrations in plasma and serum showed a strong linear correlation, however wide limits of agreement. Storage of blood samples at room temperature prior to centrifugation resulted in an exponential increase in plasma concentrations after ≈6 h. HMGB1 concentrations were fairly stable in centrifuged plasma samples subjected to long-term storage and freeze/thaw cycles. We were not able to detect HMGB1 in either serum or plasma from our trauma patients using western blotting. Conclusions Arterial and venous HMGB1 concentrations cannot be directly compared, and concentration values in plasma and serum must be compared with caution due to wide limits of agreement. Although HMGB1 levels in clinical samples from trauma patients are fairly stable, strict adherence to a pre-analytical protocol is advisable in order to protect sample integrity. Surprisingly, we were unable to detect HMGB1 utilizing standard western blot analysis.

Patulin production by Penicillium expansum isolates from apples during different steps of long-term storage

2016 ◽  
Vol 9 (3) ◽  
pp. 379-388 ◽  
Author(s):  
N. De Clercq ◽  
G. Vlaemynck ◽  
E. Van Pamel ◽  
D. Colman ◽  
M. Heyndrickx ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Penicillium Expansum ◽  
Penicillium Species ◽  
Cold Temperatures ◽  
Long Term Storage ◽  
In Vitro Investigation ◽  
Duration Of Storage ◽  
Term Storage

Penicillium expansum is the principal cause of blue mould rot and associated production of patulin, a weak mycotoxin, in apples worldwide. P. expansum growth and patulin production is observed during improper or long-term storage of apples. We have investigated the extent to which each successive step during long-term storage contributes to patulin production in various P. expansum isolates. Fungal isolates collected on apples from several Belgian orchards/industries were identified to species level. Random amplification of polymorphic DNA (RAPD) analysis and β-tubulin gene sequencing identified P. expansum and Penicillium solitum as the most prevalent Penicillium species associated with Belgian apples. All 27 P. expansum isolates and eight reference strains were characterised for their patulin production capacity on apple puree agar medium for five days under classical constant temperature and atmosphere conditions. Under these conditions, a large range of patulin production levels was observed. Based on this phenotypic diversity, five P. expansum isolates and one reference strain were selected for in vitro investigation of patulin production under representative conditions in each step of long-term apple storage. Patulin accumulation seemed highly strain dependent and no significant differences between the storage steps were observed. The results also indicated that a high spore inoculum may lead to a strong patulin accumulation even at cold temperatures (1 °C) combined with controlled atmosphere (CA) (3% O2, 1% CO2), suggesting that future control strategies may benefit from considering the duration of storage under CA conditions as well as duration of deck storage.

scholarly journals Effect of Long-Term Storage on Mycobiota of Barley Grain and Malt

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1655
Author(s):  
Soňa Felšöciová ◽  
Przemysław Łukasz Kowalczewski ◽  
Tomáš Krajčovič ◽  
Štefan Dráb ◽  
Miroslava Kačániová
Keyword(s):  
Barley Grain ◽  
In Vitro Assays ◽  
Production Cycle ◽  
Microscopic Fungi ◽  
Microbiome Composition ◽  
Long Term Storage ◽  
Fungal Microbiome ◽  
Term Storage

Contamination of malting barley grain and malt with micromycetes sampled at various periods post-harvest (3rd, 6th, and 9th month of storage) and types of storage (storage silo and floor warehouse) was investigated. Each of these barley grain samples was malted. This article reports on the changes in the fungal microbiome composition and their overall count in barley grain and malt. From the surface-disinfected barley grain samples collected immediately after harvest, there were eight genera isolated, with a predominance of Alternaria. A small increase of isolated microfungi was detected in barley stored in silo for 3 and 6 months (from 142 isolates to 149) and decreased below the number of isolates in barley before storage (133 isolates). Fungal count during storage gradually decreased up to 9 month in barley stored in floor warehouse (from 142 isolates to 84). The initial total count of microscopic fungi in malt before storage was the highest (112 isolates) with 7 genera detected, compared to malts prepared from barley stored for longer time (54 isolates, 7 genera, 9th month of storage). Alternaria was the most abundant and frequent genus. Quantitative representation of the filamentous microscopic fungi was lower compared to yeasts especially in barley and malt prepared from barley stored at third month of storage in both type of storage. Yeasts were identified from all grain samples and malt samples with mass spectrometry. Most attention was given to the widely distributed fungus Penicillium, 79% of strains produced at least one mycotoxin detected under in vitro assays using the TLC method (97% of them produced griseofulvin, 94% CPA, 79% patulin, 14% roquefortin C, and penitrem A was produced by two screening strains under laboratory conditions). It is therefore important to monitor the microflora throughout the production cycle of “barley to beer”.

scholarly journals Preservation of In Vitro Grown Shoot Tips of Potato (Solanum tuberosum L.) by Different Methods of Cryopreservation

1970 ◽  
Vol 10 ◽  
pp. 15-20
Author(s):  
Shambhu P. Dhital ◽  
Hira K. Manandhar ◽  
Hak T. Lim
Keyword(s):  
Sucrose Concentration ◽  
Shoot Tips ◽  
Efficient Tool ◽  
Long Term Storage ◽  
In Vitro Plantlets ◽  
Tuber Morphology ◽  
Vegetatively Propagated Plants ◽  
Term Storage

Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of sucrose concentration, hardening temperature and different cryopreservation methods on the survival rate of potato shoot tips after cryopreservation. Excised shoot tips of in vitro plantlets of potato cultivars, Atlantic and Superior were cryopreserved by vitrification, encapsulationvitrification and encapsulation-dehydration. Cryopreservation by vitrification method was used to determine the optimum concentration of sucrose and cold hardening temperature during sub-culturing period to the donor plantlets. Nine-percent sucrose gave 46.7% survival in Atlantic and 40% in Superior. The most optimum hardening temperature for 50% survival in Atlantic and 43.3% in Superior was 10°C. In the case of comparative study of three different cryopreservation methods, the highest survival (52%) as well as regeneration (46%) were observed when the shoot tips were cryopreserved by encapsulation-vitrification method, and the lowest survival (36%) and regeneration (28%) from the vitrification. Plant and tuber morphology of potato regenerated after cryopreservation were similar to those of the non-cryopreserved in vitro plantlets (control). Thus, this study demonstrated that encapsulation-vitrification method was the most effective one among other methods for higher survival as well as regeneration in in vitro shoot tips of potato.Key words: Cryopreservation; Dehydration; Encapsulation; Potato; Regeneration; VitrificationDOI: 10.3126/njst.v10i0.2804Nepal Journal of Science and Technology Volume 10, 2009 December Page: 15-20

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