Gamma-hydroxybutyric acid endogenous production and post-mortem behaviour – The importance of different biological matrices, cut-off reference values, sample collection and storage conditions

2014 ◽  
Vol 27 ◽  
pp. 17-24 ◽  
Author(s):  
André L. Castro ◽  
Mário Dias ◽  
Flávio Reis ◽  
Helena M. Teixeira
Keyword(s):  
Reference Values ◽  
Storage Conditions ◽  
Post Mortem ◽  
Hydroxybutyric Acid ◽  
Sample Collection ◽  
Biological Matrices ◽  
Endogenous Production ◽  
And Storage

Variability in, variability out: best practice recommendations to standardize pre-analytical variables in the detection of circulating and tissue microRNAs

2017 ◽  
Vol 55 (5) ◽  
Author(s):  
Jenna Khan ◽  
Joshua A. Lieberman ◽  
Christina M. Lockwood
Keyword(s):  
Best Practice ◽  
Rna Extraction ◽  
Storage Conditions ◽  
Sample Collection ◽  
Ischemic Time ◽  
Cold Ischemic Time ◽  
C Storage ◽  
Tissue Specimens ◽  
And Storage

Abstract:microRNAs (miRNAs) hold promise as biomarkers for a variety of disease processes and for determining cell differentiation. These short RNA species are robust, survive harsh treatment and storage conditions and may be extracted from blood and tissue. Pre-analytical variables are critical confounders in the analysis of miRNAs: we elucidate these and identify best practices for minimizing sample variation in blood and tissue specimens. Pre-analytical variables addressed include patient-intrinsic variation, time and temperature from sample collection to storage or processing, processing methods, contamination by cells and blood components, RNA extraction method, normalization, and storage time/conditions. For circulating miRNAs, hemolysis and blood cell contamination significantly affect profiles; samples should be processed within 2 h of collection; ethylene diamine tetraacetic acid (EDTA) is preferred while heparin should be avoided; samples should be “double spun” or filtered; room temperature or 4 °C storage for up to 24 h is preferred; miRNAs are stable for at least 1 year at –20 °C or –80 °C. For tissue-based analysis, warm ischemic time should be <1 h; cold ischemic time (4 °C) <24 h; common fixative used for all specimens; formalin fix up to 72 h prior to processing; enrich for cells of interest; validate candidate biomarkers with in situ visualization. Most importantly, all specimen types should have standard and common workflows with careful documentation of relevant pre-analytical variables.

Effects of sample collection and storage conditions on DNA damage in buccal cells from agricultural workers

2011 ◽  
Vol 720 (1-2) ◽  
pp. 8-13 ◽  
Author(s):  
Juan F. Muniz ◽  
Linda A. McCauley ◽  
Victoria Pak ◽  
Michael R. Lasarev ◽  
Glen E. Kisby
Keyword(s):  
Dna Damage ◽  
Storage Conditions ◽  
Agricultural Workers ◽  
Sample Collection ◽  
Buccal Cells ◽  
And Storage

scholarly journals Effects of Temperature on Stability of Blood Homocysteine in Collection Tubes Containing 3-Deazaadenosine

2002 ◽  
Vol 48 (11) ◽  
pp. 2017-2022 ◽  
Author(s):  
Diane M Hill ◽  
Lisa J Johnson ◽  
Paul J Burns ◽  
Angela M Neale ◽  
Denise M Harmening ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Time Course ◽  
Hospital Setting ◽  
Storage Conditions ◽  
Effect Of Temperature ◽  
Sample Collection ◽  
Within Subjects ◽  
Effects Of Temperature ◽  
The Stability ◽  
And Storage

Abstract Background: The accuracy of homocysteine (Hcy) results is currently compromised by the requirement to separate the plasma within 1 h of sample collection. We studied the effect of temperature on the stability of plasma Hcy over a 72-h time course in blood collected into evacuated tubes containing either EDTA alone or both EDTA and 3-deazaadenosine (3DA). Methods: We recruited 100 volunteers, including both diseased and healthy individuals with a range of baseline plasma Hcy values, from two centers. Blood samples were collected into tubes containing EDTA, and EDTA plus 3DA and stored at ambient temperature (20–25 °C) or refrigerated (2–8 °C). Aliquots of blood were centrifuged at various times up to 72 h, the plasma was removed, and Hcy was measured by HPLC. Results: Plasma Hcy measurement covering the sample collection and storage conditions during the whole time course was possible on samples from 59 of those recruited. One-way ANOVA for repeated measures within subjects revealed that only samples that were collected into tubes containing EDTA plus 3DA and stored refrigerated were stable over 72 h (P = 0.2761). Conclusions: A combination of 3DA and storage at 2–8 °C will allow collection of samples for plasma Hcy measurement outside of the hospital setting and wider population screening.

scholarly journals Delivery of High-Quality Biomarker Assays

2002 ◽  
Vol 18 (2) ◽  
pp. 47-56 ◽  
Author(s):  
Brian N. Swanson
Keyword(s):  
Disease Process ◽  
Clinical Pathology ◽  
Storage Conditions ◽  
Quality Data ◽  
Sample Collection ◽  
High Quality ◽  
Exposure Response ◽  
Specificity And Sensitivity ◽  
Safety Studies ◽  
And Storage

Biomarker measurements now support key decisions throughout the drug development process, from lead optimization to regulatory approvals. They are essential for documenting exposure-response relationships, specificity and potency toward the molecular target, untoward effects, and therapeutic applications. In a broader sense, biomarkers constitute the basis of clinical pathology and laboratory medicine. The utility of biomarkers is limited by their specificity and sensitivity toward the drug or disease process and by their overall variability. Understanding and controlling sources of variability is not only imperative for delivering high-quality assay results, but ultimately for controlling the size and expense of research studies. Variability in biomarker measurements is affected by: biological and environmental factors (e.g., gender, age, posture, diet and biorhythms), sample collection factors (e.g., preservatives, transport and storage conditions, and collection technique), and analytical factors (e.g., purity of reference material, pipetting precision, and antibody specificity). The quality standards for biomarker assays used in support of nonclinical safety studies fall under GLP (FDA) regulations, whereas, those assays used to support human diagnostics and healthcare are established by CLIA (CMS) regulations and accrediting organizations such as the College of American Pathologists. While most research applications of biomarkers are not regulated, biomarker laboratories in all settings are adopting similar laboratory practices in order to deliver high-quality data. Because of the escalation in demand for biomarker measurements, the highly-parallel (multi-plexed) assay platforms that have fueled the rise of genomics will likely evolve into the analytical engines that drive the biomarker laboratories of tomorrow.

scholarly journals Important Considerations for Sample Collection in Metabolomics Studies with a Special Focus on Applications to Liver Functions

Metabolites ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 104 ◽  
Author(s):  
Lorraine Smith ◽  
Joran Villaret-Cazadamont ◽  
Sandrine P. Claus ◽  
Cécile Canlet ◽  
Hervé Guillou ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Nutritional Status ◽  
High Variability ◽  
Special Focus ◽  
Sample Collection ◽  
Biological Matrices ◽  
Standard Operating ◽  
Liver Functions ◽  
Health And Disease ◽  
And Storage

Metabolomics has found numerous applications in the study of liver metabolism in health and disease. Metabolomics studies can be conducted in a variety of biological matrices ranging from easily accessible biofluids such as urine, blood or feces, to organs, tissues or even cells. Sample collection and storage are critical steps for which standard operating procedures must be followed. Inappropriate sample collection or storage can indeed result in high variability, interferences with instrumentation or degradation of metabolites. In this review, we will first highlight important general factors that should be considered when planning sample collection in the study design of metabolomic studies, such as nutritional status and circadian rhythm. Then, we will discuss in more detail the specific procedures that have been described for optimal pre-analytical handling of the most commonly used matrices (urine, blood, feces, tissues and cells).

Effect of pH and storage conditions on measured ionised calcium concentration in dogs and cats

2020 ◽  
Vol 187 (9) ◽  
pp. e72-e72
Author(s):  
Michal Mazaki-Tovi ◽  
Shira Topol ◽  
Itamar Aroch
Keyword(s):  
Calcium Concentration ◽  
Storage Conditions ◽  
Sample Collection ◽  
Serum Samples ◽  
Aerobic Conditions ◽  
Effect Of Ph ◽  
Ionised Calcium ◽  
Clinically Significant ◽  
And Storage ◽  
Good Agreement

BackgroundAerobic blood sample collection and processing results in increased serum pH and decreased ionised calcium (iCa) concentration. This prospective study aimed to determine the effect of pH and storage conditions on measured iCa concentration in serum samples obtained from dogs and cats and establish correction formulas for use in samples obtained aerobically.MethodsBlood samples were collected from 44 dogs and 25 cats; iCa and pH were measured immediately under anaerobic conditions and in samples stored under several aerobic conditions.ResultsMeasured iCa concentrations were significantly lower in samples stored at all aerobic conditions than in samples handled anaerobically in both dogs and cats (P<0.01 for all). The largest and most clinically significant differences were noted in samples stored at −20°C for 30 days in both dogs (0.48 mmol/l; 95 per cent CI 0.40 to 0.55) and cats (0.40 mmol/l; 95 per cent CI 0.33 to 0.47). Correction formulas (corrected iCa=measured iCa+coefficient × (measured pH–7.41); coefficient=0.597 for dogs, 0.627 for cats) yielded good agreement between the corrected and the actual iCa concentrations.ConclusionsSamples for iCa measurement can be stored at either 4°C or −20°C for 24 hours. Storage at −80°C is recommended for longer storage time periods.

scholarly journals Collection of Human Genomic DNA From Buccal Cells for Genetics Studies: Comparison Between Cytobrush, Mouthwash, and Treated Card

2005 ◽  
Vol 2005 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Claire Mulot ◽  
Isabelle Stücker ◽  
Jacqueline Clavel ◽  
Philippe Beaune ◽  
Marie-Anne Loriot
Keyword(s):  
Large Scale ◽  
Storage Conditions ◽  
Sample Collection ◽  
Buccal Cells ◽  
Genetic Studies ◽  
Dna Yield ◽  
Dna Collection ◽  
Alternative Sources ◽  
And Storage

Alternative sources such as buccal cells have already been tested for genetic studies and epidemiological investigations. Thirty-seven volunteers participated in this study to compare cytology brushes, mouthwash, and treated cards for DNA collection. Quantity and quality of DNA and cost and feasibility were assessed. The mean DNA yield at 260 nm was found to be3.5,4, and2.6μg for cytobrushes, mouthwashes, and treated cards, respectively. A second quantification technique by fluorescence showed differences in the DNA yield with1.1and5.2μg for cytobrushes and mouthwash, respectively. All buccal samples allowed isolation of DNA suitable for polymerase chain reaction. According to the procedure of sample collection, the yield and purity of collected DNA, and storage conditions, the use of cytobrush appears to be the more appropriate method for DNA collection. This protocol has been validated and is currently applied in three large-scale multicentric studies including adults or children.

Effect of Sample Collection and Storage Conditions on DNA Damage in Buccal Cells From Agricultural Workers

Epidemiology ◽  
2011 ◽  
Vol 22 ◽  
pp. S237-S238
Author(s):  
Juan F. Muniz ◽  
Linda A. McCauley ◽  
Victoria Pak ◽  
Michael R. Lasarev ◽  
Glen E. Kisby
Keyword(s):  
Dna Damage ◽  
Storage Conditions ◽  
Agricultural Workers ◽  
Sample Collection ◽  
Buccal Cells ◽  
And Storage

Evaluation of preanalytical variables associated with measurement of prothrombin fragment 1.2

1994 ◽  
Vol 40 (10) ◽  
pp. 1962-1969 ◽  
Author(s):  
C S Greenberg ◽  
M J Hursting ◽  
B G Macik ◽  
T L Ortel ◽  
W H Kane ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Factor Xa ◽  
Storage Conditions ◽  
Sample Collection ◽  
Thrombotic Risk ◽  
Mean Values ◽  
Prothrombin Fragment ◽  
Acid Citrate Dextrose ◽  
Citrate Dextrose ◽  
And Storage

Abstract We have used a monoclonal antibody-based ELISA for plasma prothrombin fragment 1.2 (F1.2) to establish appropriate sample collection and storage conditions for this biomarker of thrombin generation. F1.2 concentrations were not altered by exogenous factor Xa, thrombin, or thromboplastin if blood was collected by routine venipuncture into tubes containing heparin as anticoagulant (but not citrate, acid-citrate-dextrose, EDTA, or oxalate) and if plasma antithrombin III concentration was &gt; or = 30% of normal. Heparinized plasma F1.2 was stable for &gt; or = 8 h at 20-25 degrees C, and if premixed with a stabilizing reagent, for &gt; or = 4 years at -70 degrees C. Mean values for heparinized plasma F1.2 collected and stored by recommended procedures were increased in patients with thrombosis and conditions of increased thrombotic risk, and were sensitive to heparin and oral anticoagulant therapies. We conclude that plasma obtained by routine venipuncture into tubes with heparin as anticoagulant is an appropriate specimen for F1.2 measurements for most patients.

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