scholarly journals An Internal Control for Routine Diagnostic PCR: Design, Properties, and Effect on Clinical Performance

1998 ◽  
Vol 36 (1) ◽  
pp. 191-197 ◽  
Author(s):  
Maurice Rosenstraus ◽  
Zhuang Wang ◽  
Sheng-Yung Chang ◽  
David DeBonville ◽  
Joanne P. Spadoro

We constructed internal controls (ICs) to provide assurance that clinical specimens are successfully amplified and detected. The IC nucleic acids contain primer binding regions identical to those of the target sequence and contain a unique probe binding region that differentiates the IC from amplified target nucleic acid. Because only 20 copies of the IC are introduced into each test sample, a positive IC signal indicates that amplification was sufficient to generate a positive signal from targets present at the limit of test sensitivity. The COBAS AMPLICOR Chlamydia trachomatis, Neisseria gonorrhoeae, Mycobacterium tuberculosis, and human hepatitis C virus tests exhibited inhibition rates ranging from 5 to 9%. Approximately 64% of these inhibitory specimens were not inhibitory when a second aliquot was tested. Because repeatedly inhibitory specimens were not reported as false negative and because additional infected specimens were detected during retesting, test sensitivities were 1 to 6% greater than they would have been if the IC had not been used.

1998 ◽  
Vol 36 (7) ◽  
pp. 1919-1922 ◽  
Author(s):  
Dien G. Pham ◽  
Guillermo E. Madico ◽  
Thomas C. Quinn ◽  
Mark J. Enzler ◽  
Thomas F. Smith ◽  
...  

An inherent problem in the diagnostic PCR assay is the presence of ill-defined inhibitors of amplification which may cause false-negative results. Addition of an amplifiable fragment of foreign DNA in the PCR to serve as a hybrid internal control (HIC) would allow for a simple way to identify specimens containing inhibitors. Two oligonucleotide hybrid primers were synthesized to contain nucleic acid sequences of the Chlamydia pneumoniae 16S rRNA primers in a position flanking two primers that target the sequences of a 650-bp lambda phage DNA segment. By using the hybrid primers, hybrid DNA comprising a large sequence of lambda phage DNA flanked by short pieces of chlamydia DNA was subsequently generated by PCR, cloned into a plasmid vector, and purified. Plasmids containing the hybrid DNA were diluted and used as a HIC by adding them to each C. pneumoniae PCR test. Consequently, C. pneumoniae primers were able to amplify both chlamydia DNA and the HIC DNA. The production of a 689-bp HIC DNA band on an acrylamide gel indicated that the specimen contained no inhibitors and that internal conditions were compatible with PCR. Subsequently, a biotinylated RNA probe for the HIC was transcribed from a nested sequence of the HIC and was used for its hybridization. Detection of the HIC DNA-RNA hybrid was achieved by enzyme immunoassay (EIA). This PCR-EIA system with a HIC was initially tested with 12 previously PCR-positive and 14 previously PCR-negative specimens. Of the 12 PCR-positive specimens, 11 were reconfirmed as positive; 1 had a negative HIC value, indicating inhibition. Of the 14 previously PCR-negative specimens, 13 were confirmed as true negative; 1 had a negative HIC value, indicating inhibition. The assay was then used with 237 nasopharyngeal specimens from patients with pneumonia. Twenty-one of 237 (8.9%) were positive for C. pneumoniae, and 42 (17.7%) were found to inhibit the PCR. Specimens showing inhibitory activity were diluted 1:10 and were retested. Ten specimens were still inhibitory to the PCR and required further DNA purification. No additional positive samples were detected and 3 nasopharyngeal specimens remained inhibitory to PCR. Coamplification of a HIC DNA can help confirm true-negative PCR results by ruling out the presence of inhibitors of DNA amplification.


2020 ◽  
Author(s):  
Aitor González ◽  
Vincent Dubut ◽  
Emmanuel Corse ◽  
Reda Mekdad ◽  
Thomas Dechatre ◽  
...  

AbstractMetabarcoding studies should be carefully designed to minimize false positives and false negative occurrences. The use of internal controls, replicates, and several overlapping markers is expected to improve the bioinformatics data analysis.VTAM is a tool to perform all steps of data curation from raw fastq data to taxonomically assigned ASV (Amplicon Sequence Variant or simply variant) table. It addresses all known technical error types and includes other features rarely present in existing pipelines for validating metabarcoding data: Filtering parameters are obtained from internal control samples; cross-sample contamination and tag-jump are controlled; technical replicates are used to ensure repeatability; it handles data obtained from several overlapping markers.Two datasets were analysed by VTAM and the results were compared to those obtained with a pipeline based on DADA2. The false positive occurrences in samples were considerably higher when curated by DADA2, which is likely due to the lack of control for tag-jump and cross-sample contamination.VTAM is a robust tool to validate metabarcoding data and improve traceability, reproducibility, and comparability between runs and datasets.


2019 ◽  
Vol 32 (6) ◽  
pp. 758-766 ◽  
Author(s):  
Lifang Yan ◽  
Kathy L. Toohey-Kurth ◽  
Beate M. Crossley ◽  
Jianfa Bai ◽  
Amy L. Glaser ◽  
...  

Many of the sample matrices typically used for veterinary molecular testing contain inhibitory factors that can potentially reduce analytic sensitivity or produce false-negative results by masking the signal produced by the nucleic acid target. Inclusion of internal controls in PCR-based assays is a valuable strategy not only for monitoring for PCR inhibitors, but also for monitoring nucleic acid extraction efficiency, and for identifying technology errors that may interfere with the ability of an assay to detect the intended target. The Laboratory Technology Committee of the American Association of Veterinary Laboratory Diagnosticians reviewed the different types of internal controls related to monitoring inhibition of PCR-based assays, and provides information here to encourage veterinary diagnostic laboratories to incorporate PCR internal control strategies as a routine quality management component of their molecular testing.


2014 ◽  
pp. 55-77
Author(s):  
Tatiana Mazza ◽  
Stefano Azzali

This study analyzes the severity of Internal Control over Financial Reporting deficiencies (Deficiencies, Significant Deficiencies and Material Weaknesses) in a sample of Italian listed companies, in the period 2007- 2012. Using proprietary data the severity of the deficiencies is tested for account-specific, entity level and information technology controls and for industries (manufacturing and services vs finance industries). The results on ICD severity is compared with one of the most frequent ICD (Acc_Period End/Accounting Policies): for account-specific, ICD in revenues, purchase, fixed assets and intangible, loans and insurance are more severe while ICD in Inventory are less severe. Differences in ICD severity have been found in the characteristic account: ICD in loan and insurance for finance industry and ICD in revenue, purchase for manufacturing and service industry are more severe. Finally, we found that ICD in entity level and information technology controls are less severe than account specific ICD in all industries. However, the results on entity level and information technology deficiencies could also mean that the importance of these types of control are under-evaluated by the manufacturing and service companies.


ProBank ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 64-75
Author(s):  
Prima Utama Wardoyo Putro

Law No 32 year on 2004 about Regional Government and Law No 33 years on 2004 about Fiscal Balance between the Central Government and Regional Government are a new regulation relating to the implementation of regional autonomy in Indonesia. Giving the authority to manage its own region required an internal control system that can monitor of all by central government. The problem in this study is: Is there are any influence between growth, size, and PAD through Regional Government Internal Controls weakness with PAD as an intervening variable. The research populations are the financial statements and reports on the results of the entire province in Indonesia totaling 33 provinces. Source of data which are used are secondary data, and data collection by using the documentation method. The results of partial testing showed that PAD and Growth have significant affects to the Internal Controls, whereas size has not significant effect. Simultaneous testing showed a significant effect between the independent and dependent variables. The test results path testing showed that growth has no significant effect to internal control through PAD as an intervening variable and size has a significant effect to internal control variable through PAD as an intervening variable. The results of determinant coefficient by simultan test amount 28.7%. Its mean that Internal Control can be explained by Growth, Size and PAD, the remaining 71.3% influenced by factors other than study. Keyword: Internal Control, Size, Growth, and Income


2015 ◽  
Vol 30 (1) ◽  
pp. 119-141 ◽  
Author(s):  
Tuukka Järvinen ◽  
Emma-Riikka Myllymäki

SYNOPSIS The purpose of this study is to investigate whether SOX Section 404 material weaknesses manifest in real earnings management behavior. The empirical findings indicate that, compared to companies with effective internal controls, companies with existing material weaknesses in their internal controls engage in more manipulation of real activities (particularly inventory overproduction). This implies that the weak commitment by management to provide effective internal control system and high-quality financial information relates to a tendency to use real earnings management methods. Moreover, we find evidence suggesting that companies employ real earnings management (overproduction and reduction of discretionary expenses) after disclosing previous year's material weaknesses. We conjecture that the public disclosure of material weaknesses induces management to strive to mitigate the expected negative reactions of stakeholders to the disclosure by engaging in real earnings management, which is not easily detected or constrained by outsiders. Overall, this study suggests that material weaknesses in internal controls signal an environment where management is more inclined to employ real earnings management.


2020 ◽  
Vol 47 (1) ◽  
pp. 55-74
Author(s):  
Ryan P. McDonough ◽  
Paul J. Miranti ◽  
Michael P. Schoderbek

ABSTRACT This paper examines the administrative and accounting reforms coordinated by Herman A. Metz around the turn of the 20th century in New York City. Reform efforts were motivated by deficiencies in administering New York City's finances, including a lack of internal control over monetary resources and operational activities, and opaque financial reports. The activities of Comptroller Metz, who collaborated with institutions such as the New York Bureau of Municipal Research, were paramount in initiating and implementing the administrative and accounting reforms in the city, which contributed to reform efforts across the country. Metz promoted the adoption of functional cost classifications for city departments, developed flowcharts for improved transaction processing, strengthened internal controls, and published the 1909 Manual of Accounting and Business Procedure of the City of New York, which laid the groundwork for transparent financial reports capable of providing vital information about the city's activities and subsidiary units. JEL Classifications: H72, M41, N91. Data Availability: Data are available from the public sources cited in the text.


2015 ◽  
Vol 29 (3) ◽  
pp. 551-575 ◽  
Author(s):  
Colleen M. Boland ◽  
Scott N. Bronson ◽  
Chris E. Hogan

SYNOPSIS We examine whether regulations requiring accelerated filing deadlines and internal control reporting and testing affect financial statement reliability. Unlike prior research, we examine whether these regulatory changes are associated with an increase in the likelihood that misstatements originate in the period following the respective change. If the implementation of these rules causes a misstatement, then the misstatement would most likely occur in the period immediately following the rule change. We provide evidence that accelerated filers (AFs) experience an increase in the likelihood of an originating misstatement following the acceleration of filing deadlines from 90 to 75 days. Large accelerated filers (LAFs), however, do not experience a similar increase following this acceleration or the subsequent acceleration from 75 to 60 days. After the implementation of the SOX Section 404 internal control requirements, we find that the likelihood of an originating misstatement declined for AFs but not for LAFs. Taken together, the findings suggest that, although AFs experienced an initial decrease in financial statement reliability, this decrease was temporary. Data Availability: Data are publicly available from the sources identified in the text.


2016 ◽  
Vol 36 (2) ◽  
pp. 45-62 ◽  
Author(s):  
Yangyang Chen ◽  
W. Robert Knechel ◽  
Vijaya Bhaskar Marisetty ◽  
Cameron Truong ◽  
Madhu Veeraraghavan

SUMMARY In this paper, we investigate whether board independence has an impact on the likelihood that a company reports weaknesses in internal controls. Using a sample of 11,226 firm-year observations spanning the period 2004–2012, we establish several findings. First, we document a negative relation between board independence and the disclosure of internal control weaknesses. We also document that the negative relation is stronger for firms with unitary leadership (combined positions of CEO and chairman) than for firms with dual leadership. Next, we show that board independence is associated with both fewer account-specific and company-level weaknesses. Finally, we show that board independence is associated with timely remediation of internal control weaknesses and that the implementation of Auditing Standard No. 5 in 2007 weakens the effect of board independence on the disclosure of ICW. JEL Classifications: G10; G18.


2016 ◽  
Vol 35 (4) ◽  
pp. 159-173 ◽  
Author(s):  
Byron J. Pike ◽  
Lawrence Chui ◽  
Kasey A. Martin ◽  
Renee M. Olvera

SUMMARY To reduce redundancies and increase efficiency in the evaluation of internal controls (PCAOB 2007, 402–403), professional standards encourage coordination between external auditors and their clients' internal audit function (IAF). Recent surveys of internal auditors find that a component of this coordination is external auditors' involvement in developing the IAF's audit plans. Nevertheless, it is not known how such involvement affects external auditors' reliance on the internal control test work of the IAF, either before or after a negative audit discovery. Based on an experiment with 107 experienced auditors, we find that external auditors involved in the development of the IAF's audit plan perceive the IAF as more objective and that both objectivity and involvement contribute to these auditors' placing more reliance on the IAF as compared to external auditors with no involvement. This initial reliance results in the involved auditors' proposing reductions to the audit budget and re-performing less of the IAF's work. Consistent with an anchoring bias, we find that involvement leads to external auditors' continuing to place greater reliance on the IAF's work, even after they become aware of a negative audit discovery that should not have occurred had the client's controls been effective. Data Availability: Data are available from the authors on request.


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