Use of Coefficient of Variation in Assessing Variability of Quantitative Assays

Reed, George F.; Lynn, Freyja; Meade, Bruce D.

doi:10.1128/cdli.10.6.1162.2003

Cited by 160 publications

(184 citation statements)

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“…Table SI-2 summarizes the results for the interlaboratory test. The relative standard deviation (RSD) of the mean concentrations of COC and BE analyzed by the two laboratories was in all cases lower than the recommended cutoff value of 20% (Reed et al, 2002). This is for the first time that an interlaboratory test is reported for the analysis of COC and metabolites in waste water.…”

Section: Quality Control -Quality Assurancementioning

confidence: 69%

Cocaine and metabolites in waste and surface water across Belgium

Nuijs

Pecceu

Theunis

et al. 2009

Environmental Pollution

127

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Cocaine consumption can be evaluated through analysis of waste and surface water. Cocaine abuse, a growing social problem, is currently estimated from population surveys, consumer interviews and crime statistics. A new approach based on the analysis of cocaine (COC) and metabolites, benzoylecgonine (BE) and ecgonine methyl ester (EME), in water samples was applied to 28 rivers and 37 waste water treatment plants in Belgium using solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry. While EME was undetectable, COC and BE were detectable with concentrations ranging from <1 to 753 ng/L and <1 to 2258 ng/L, respectively. BE concentrations were employed to calculate the local amount of abused cocaine. The highest values (up to 1.8 g/day cocaine per 1000 inhabitants) were found in large cities and during weekends. The estimation of cocaine abuse through water analysis can be executed on regular basis without cooperation of patients. It also gives clear geographical information, while prevention campaigns can easily be implemented and evaluated. a r t i c l e i n f o

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Section: Quality Control -Quality Assurancementioning

confidence: 69%

Cocaine and metabolites in waste and surface water across Belgium

Nuijs

Pecceu

Theunis

et al. 2009

Environmental Pollution

127

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“…Every serum sample was tested in duplicate; plate-to-plate variation of the optical density values (OD-value) was corrected by using linear regression on the control sera tested on every plate . A plate was retested if replicates of one control had a coefficient of variation (CV) above 20% (Reed et al, 2002), or if the mean OD-value of the positive control was lower than 0.350 and/or the ratio of the mean OD-value of the positive and negative controls was lower than 3. Individual sera were retested if the replicates showed different statuses according to the cut-off values provided by the manufacturer.…”

Section: Serological Assaymentioning

confidence: 99%

Experimental studies on Toxoplasma gondii in the main livestock species (GP/EFSA/BIOHAZ/2013/01) Final report

Opsteegh

Schares

Blaga

et al. 2016

EFS3

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After extensive review of the literature, experimental studies were performed in the main livestock species (cattle, small ruminants, pigs, horses and poultry) to address the main knowledge gaps considering (1) the relationship between detection of antibodies and presence of T. gondii, (2) the anatomical distribution of tissue cysts, and (3) on-farm risk factors for infection. In slaughterhouse studies in cattle and horses, a lack of concordance between detection of antibodies by MAT and detection of T. gondii in tissues by mouse bioassay or MC-PCR was demonstrated. Positive mouse bioassay results were obtained in cattle and horses, indicating a potential infection risk for consumers. DISCLAIMERThe present document has been produced and adopted by the bodies identified above as author(s). In accordance with Article 36 of Regulation (EC) No 178/2002, this task has been carried out exclusively by the author(s) in the context of a grant agreement between the European Food Safety Authority and the author(s). The present document is published complying with the transparency principle to which the Authority is subject. It cannot be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors. The present document has been produced and adopted by the bodies identified above as author(s). In accordance with Article 36 of Regulation (EC) No 178/2002, this task has been carried out exclusively by the author(s) in the context of a grant agreement between the European Food Safety Authority and the author(s). The present document is published complying with the transparency principle to which the Authority is subject. It cannot be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors. 2In naturally infected pigs and chickens the agreement depended on assays and matrices/analytes used, but was considered fair to substantial. Calves, sheep, pigs, chickens and turkeys were experimentally infected with T. gondii. In calves various tissues were tested and T. gondii was recovered, but no clear predilection sites were identified. There was also little variation in parasite load between the different edible tissues (i.e. skeletal muscles) from pigs and sheep. Brain and heart were clearly identified as predilection sites in chickens and turkeys, with higher parasite loads compared to breast, thigh and drumstick muscle. The observation that drumstick, an edible tissue, tested positive in 25% (8/32) of the bioassay positive organic laying hens, indicated a potential risk for consumers. The seroprevalence of T. gondii in Dutch indoor-housed dairy goats appears to be relatively low and was associated with the presence of cats at the farm. I...

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“…Intra-and inter-animal variability and intermediate precision were determined by calculating the coefficient of variation (%CV). %CV is a normalized measure of the dispersion of a probable distribution and is the ratio of the standard deviation to the sample mean times 100 [26].…”

Section: Discussionmentioning

confidence: 99%

A High-Throughput Method for Direct Detection of Therapeutic Oligonucleotide-Induced Gene SilencingIn Vivo

Coles

Osborn

Alterman

et al. 2016

Nucleic Acid Therapeutics

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Preclinical development of RNA interference (RNAi)-based therapeutics requires a rapid, accurate, and robust method of simultaneously quantifying mRNA knockdown in hundreds of samples. The most well-established method to achieve this is quantitative real-time polymerase chain reaction (qRT-PCR), a labor-intensive methodology that requires sample purification, which increases the potential to introduce additional bias. Here, we describe that the QuantiGene Ò branched DNA (bDNA) assay linked to a 96-well Qiagen TissueLyser II is a quick and reproducible alternative to qRT-PCR for quantitative analysis of mRNA expression in vivo directly from tissue biopsies. The bDNA assay is a high-throughput, plate-based, luminescence technique, capable of directly measuring mRNA levels from tissue lysates derived from various biological samples. We have performed a systematic evaluation of this technique for in vivo detection of RNAi-based silencing. We show that similar quality data is obtained from purified RNA and tissue lysates. In general, we observe low intra-and inter-animal variability (around 10% for control samples), and high intermediate precision. This allows minimization of sample size for evaluation of oligonucleotide efficacy in vivo.

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Use of Coefficient of Variation in Assessing Variability of Quantitative Assays

Cited by 160 publications

References 0 publications

Cocaine and metabolites in waste and surface water across Belgium

Cocaine and metabolites in waste and surface water across Belgium

Experimental studies on Toxoplasma gondii in the main livestock species (GP/EFSA/BIOHAZ/2013/01) Final report

A High-Throughput Method for Direct Detection of Therapeutic Oligonucleotide-Induced Gene SilencingIn Vivo

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