scholarly journals Delivery of High-Quality Biomarker Assays

2002 ◽  
Vol 18 (2) ◽  
pp. 47-56 ◽  
Author(s):  
Brian N. Swanson

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.

2017 ◽  
Vol 42 (2) ◽  
pp. e13502 ◽  
Author(s):  
Nittaya Junka ◽  
Chalermchai Wongs‐Aree ◽  
Chaiwat Rattanamechaiskul

Author(s):  
Jenna Khan ◽  
Joshua A. Lieberman ◽  
Christina M. Lockwood

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.


Author(s):  
Juan F. Muniz ◽  
Linda A. McCauley ◽  
Victoria Pak ◽  
Michael R. Lasarev ◽  
Glen E. Kisby

2002 ◽  
Vol 48 (11) ◽  
pp. 2017-2022 ◽  
Author(s):  
Diane M Hill ◽  
Lisa J Johnson ◽  
Paul J Burns ◽  
Angela M Neale ◽  
Denise M Harmening ◽  
...  

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.


Author(s):  
Magdalena Leithner ◽  
Christian Fikar

Abstract Demand for and production of organic fresh food play an increasing role worldwide. As a result, a growing amount of fresh fruits and vegetables has to be transported from predominantly rural production regions to customers mostly located in urban ones. Specific handling and storage conditions need to be respected along the entire supply chain to maintain high quality and product value. To support organic food logistics operations, this work investigates benefits of facilitating real-time product data along delivery and storage processes. By the development of a simulation-based decision support system, sustainable deliveries of organic food from farms to retail stores are investigated. Generic keeping quality models are integrated to observe impacts of varying storage temperatures on food quality and losses over time. Computational experiments study a regional supply chain of organic strawberries in Lower Austria and Vienna. Results indicate that the consideration of shelf life data in supply chain decisions allow one to reduce food losses and further enables shifting surplus inventory to alternative distribution channels.


2019 ◽  
Vol 21 (1) ◽  
Author(s):  
E. Madissoon ◽  
A. Wilbrey-Clark ◽  
R. J. Miragaia ◽  
K. Saeb-Parsy ◽  
K. T. Mahbubani ◽  
...  

Abstract Background The Human Cell Atlas is a large international collaborative effort to map all cell types of the human body. Single-cell RNA sequencing can generate high-quality data for the delivery of such an atlas. However, delays between fresh sample collection and processing may lead to poor data and difficulties in experimental design. Results This study assesses the effect of cold storage on fresh healthy spleen, esophagus, and lung from ≥ 5 donors over 72 h. We collect 240,000 high-quality single-cell transcriptomes with detailed cell type annotations and whole genome sequences of donors, enabling future eQTL studies. Our data provide a valuable resource for the study of these 3 organs and will allow cross-organ comparison of cell types. We see little effect of cold ischemic time on cell yield, total number of reads per cell, and other quality control metrics in any of the tissues within the first 24 h. However, we observe a decrease in the proportions of lung T cells at 72 h, higher percentage of mitochondrial reads, and increased contamination by background ambient RNA reads in the 72-h samples in the spleen, which is cell type specific. Conclusions In conclusion, we present robust protocols for tissue preservation for up to 24 h prior to scRNA-seq analysis. This greatly facilitates the logistics of sample collection for Human Cell Atlas or clinical studies since it increases the time frames for sample processing.


2020 ◽  
Vol 187 (9) ◽  
pp. e72-e72
Author(s):  
Michal Mazaki-Tovi ◽  
Shira Topol ◽  
Itamar Aroch

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.


2005 ◽  
Vol 2005 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Claire Mulot ◽  
Isabelle Stücker ◽  
Jacqueline Clavel ◽  
Philippe Beaune ◽  
Marie-Anne Loriot

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.


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