| 1. |
- Edin, Alicia, et al.
(författare)
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Development and Laboratory Evaluation of a Real-Time PCR Assay for Detecting Viruses and Bacteria of Relevance for Community-Acquired Pneumonia
- 2015
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Ingår i: Journal of Molecular Diagnostics. - : Elsevier BV. - 1525-1578 .- 1943-7811. ; 17:3, s. 315-324
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Tidskriftsartikel (refereegranskat)abstract
- Community-acquired pneumonia may present with similar clinical symptoms, regardless of viral or bacterial cause. Diagnostic assays are needed to rapidly discriminate between causes, because this will guide decisions on appropriate treatment. Therefore, a quantitative real-time PCR (qPCR) assay with duplex reactions targeting eight bacteria and six viruses was developed. Technical performance was examined with linear plasmids. Upper and Lower respiratory tract specimens were used to compare the qPCR assay with standard microbiological methods. The limit of detection was 5 to 20 DNA template copies with approximately 1000-fold differences in concentrations of the two competing templates. SDs for positive controls were <5%. The use of the qPCR assay resulted in 113 positive identifications in 94 respiratory specimens compared with 38 by using standard diagnostics. Diagnostic accuracy of the qPCR assay varied between 60% positive agreement with standard tests for Streptococcus pneumoniae and 100% for Mycoplasma pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus. Negative percentage of agreement was >95% for M. pneumoniae, Streptococcus pyogenes, respiratory syncytial virus, and influenza A virus; whereas it was only 56% for Haemophilus influenzae. Multiple microbial agents were identified in 19 of 44 sputum and 19 of 50 nasopharynx specimens. We conclude that in parallel qPCR detection of the targeted respiratory bacteria and viruses is feasible. The results indicate good technical performance of the assay in clinical specimens.
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| 2. |
- Gréen, Anna, et al.
(författare)
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Assessment of HaloPlex Amplification for Sequence Capture and Massively Parallel Sequencing of Arrhythmogenic Right Ventricular Cardiomyopathy-Associated Genes
- 2015
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Ingår i: Journal of Molecular Diagnostics. - : Elsevier BV. - 1525-1578 .- 1943-7811. ; 17:1, s. 31-42
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Tidskriftsartikel (refereegranskat)abstract
- The genetic basis of arrhythmogenic right ventricular cardiomyopathy (ARVC) is complex. Mutations in genes encoding components of the cardiac desmosomes have been implicated as being causally related to ARVC. Next-generation sequencing allows parallel sequencing and duplication/deletion analysis of many genes simultaneously, which is appropriate for screening of mutations in disorders with heterogeneous genetic backgrounds. We designed and validated a next-generation sequencing test panel for ARVC using HaloPlex. We used SureDesign to prepare a HaloPlex enrichment system for sequencing of DES, DSC2, DSG2, DSP, JUP, PKP2, RYR2, TGFB3, TMEM43, and TIN from patients with ARVC using a MiSeq instrument. Performance characteristics were determined by comparison with Sanger, as the gold standard, and TruSeq Custom Amplicon sequencing of DSC2, DSG2, DSP, JUP, and PKP2. All the samples were successfully sequenced after HaloPlex capture, with >99% of targeted nucleotides covered by >20x. The sequences were of high quality, although one problematic area due to a presumptive context-specific sequencing error causing motif Located in exon 1 of the DSP gene was detected. The mutations found by Sanger sequencing were also found using the HaloPlex technique. Depending on the bioinformatics pipeline, sensitivity varied from 99.3% to 100%, and specificity varied from 99.90/0 to 100%. Three variant positions found by Sanger and HaloPlex sequencing were missed by TruSeq Custom Amplicon owing to Loss of coverage.
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| 3. |
- Lillsunde-Larsson, Gabriella, 1971-, et al.
(författare)
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Evaluation of HPV Genotyping Assays for Archival Clinical Samples
- 2015
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Ingår i: Journal of Molecular Diagnostics. - New York, USA : Elsevier. - 1525-1578 .- 1943-7811. ; 17:3, s. 293-301
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Tidskriftsartikel (refereegranskat)abstract
- Human papillomavirus (HPV) testing and genotyping of FFPE tissue samples is important in epidemiological investigations. Here, we compare four different HPV genotyping methods for use in FFPE clinical samples. Comparative testing was performed on 99 samples with a clinical suspicion of HPV. Specimens were analyzed with Anyplex II HPV28 detecting 28 genotypes using real-time PCR and melting curve analysis, CLART HPV2 detecting 35 genotypes using PCR and microarray detection, and MGP5+/6+ consensus primer system together with pyrosequencing. Results were compared to a real-time PCR reference protocol detecting 14 genotypes. In total, 68% of the samples were positive for an HPV genotype using the reference protocol and MGP5+/6+ primer system. Anyplex II HPV28 analysis and CLART HPV2 had 82% and 72% positive samples, respectively. All four methods showed good agreement when comparing the 14 genotypes included in the reference protocol. When evaluating all genotypes, the Anyplex II HPV28 assay and the CLART assay changed the status of the sample (individually or together) from negative with respect to the reference protocol to positive for either a Group 1 (n = 4) or Group 2 (n = 6) genotype. We conclude from this study that for an extended genotyping approach with a high sensitivity for FFPE specimens, both the Anyplex II HPV28 and CLART HPV2 assays are suitable alternatives despite minor intra-assay differences.
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| 5. |
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| 6. |
- Moens, Lotte N. J., et al.
(författare)
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HaloPlex Targeted Resequencing for Mutation Detection in Clinical Formalin-Fixed, Paraffin-Embedded Tumor Samples
- 2015
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Ingår i: Journal of Molecular Diagnostics. - : Elsevier BV. - 1525-1578 .- 1943-7811. ; 17:6, s. 729-739
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, the advent of massively parallel next-generation sequencing technologies has enabled substantial advances in the study of human diseases. Combined with targeted DNA enrichment methods, high sequence coverage can be obtained for different genes simultaneously at a reduced cost per sample, creating unique opportunities for clinical cancer diagnostics. However, the formalin-fixed, paraffin-embedded (FFPE) process of tissue samples, routinely used in pathology departments, results in DNA fragmentation and nucleotide modifications that introduce a number of technical challenges for downstream biomotecular analyses. We evaluated the HaloPlex target enrichment system for somatic mutation detection in 80 tissue fractions derived from 20 clinical cancer cases with paired tumor and normal tissue available in both FFPE and fresh-frozen format. Several modifications to the standard method were introduced, including a reduced target fragment Length and two strand capturing. We found that FFPE material can be used for HaloPlex-based target enrichment and next-generation sequencing, even when starting from small amounts of DNA. By specifically capturing both strands for each target fragment, we were able to reduce the number of false-positive errors caused by FFPE-induced artifacts and Lower the detection limit for somatic mutations. We believe that the HaloPlex method presented here will be broadly applicable as a tool for somatic mutation detection in clinical cancer settings.
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| 7. |
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| 8. |
- Vickovic, Sanja, et al.
(författare)
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Toward Rare Blood Cell Preservation for RNA Sequencing
- 2015
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Ingår i: Journal of Molecular Diagnostics. - : Elsevier BV. - 1525-1578 .- 1943-7811. ; 17:4, s. 352-359
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Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by various events Leading to cell differentiation and disease progression. Molecular tools are powerful approaches for describing how and why these events occur. With the growing field of next-generation DNA sequencing, there is an increasing need for high-quality nucleic acids derived from human cells and tissues a prerequisite for successful cell profiting. Although advances in RNA preservation have been made, some of the largest biobanks still do not employ RNA blood preservation as standard because of Limitations in low blood-input volume and RNA stability over the whole gene body. Therefore, we have developed a robust protocol for blood preservation and tong-term storage while maintaining RNA integrity. Furthermore, we explored the possibility of using the protocol for preserving rare cell samples, such as circulating tumor cells. The results of our study confirmed that gene expression was not impacted by the preservation procedure (r(2) > 0.88) or by Long-term storage (r(2) = 0.95), with RNA integrity number values averaging over 8. Similarly, cell surface antigens were still available for antibody selection (r(2) = 0.95). Lastly, data mining for fusion events showed that it was possible to detect rare tumor cells among a background of other cells present in blood irrespective of fixation. Thus, the developed protocol would be suitable for rare blood cell preservation followed by RNA sequencing analysis.
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| 9. |
- He, H. J., et al.
(författare)
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Multilaboratory Assessment of a New Reference Material for Quality Assurance of Cell-Free Tumor DNA Measurements
- 2019
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Ingår i: Journal of Molecular Diagnostics. - : Elsevier BV. - 1525-1578. ; 21:4, s. 658-676
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Tidskriftsartikel (refereegranskat)abstract
- We conducted a multilaboratory assessment to determine the suitability of a new commercially available reference material with 40 cancer variants in a background of wild-type DNA at four different variant allele frequencies (VAFs): 2%, 0.50%, 0.125%, and 0%. The variants include single nucleotides, insertions, deletions, and two structural variations selected for their clinical importance and to challenge the performance of next-generation sequencing (NGS) methods. Fragmented DNA was formulated to simulate the size distribution of circulating wild-type and tumor DNA in a synthetic plasma matrix. DNA was extracted from these samples and characterized with different methods and multiple laboratories. The various extraction methods had differences in yield, perhaps because of differences in chemistry. Digital PCR assays were used to measure VAFs to compare results from different NGS methods. Comparable VAFs were observed across the different NGS methods. This multilaboratory assessment demonstrates that the new reference material is an appropriate tool to determine the analytical parameters of different measurement methods and to ensure their quality assurance.
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