AIM To investigate and compare the analytical and clinical performance of Tian Long automatic hypersensitive hepatitis B virus(HBV) DNA quantification system and Roche CAP/CTM system.METHODS Two hundred blood samples ...AIM To investigate and compare the analytical and clinical performance of Tian Long automatic hypersensitive hepatitis B virus(HBV) DNA quantification system and Roche CAP/CTM system.METHODS Two hundred blood samples for HBV DNA testing, HBV-DNA negative samples and high-titer HBV-DNA mixture samples were collected and prepared. National standard materials for serum HBV and a worldwide HBV DNA panel were employed for performance verification. The analytical performance, such as limit of detection, limit of quantification, accuracy, precision, reproducibility, linearity, genotype coverage and cross-contamination, was determined using the Tian Long automatic hypersensitive HBV DNA quantification system(TL system). Correlation and Bland-Altman plot analyses were carried out to compare the clinical performance of the TL system assay and the CAP/CTM system. RESULTS The detection limit of the TL system was 10 IU/m L, and its limit of quantification was 30 IU/m L. The differences between the expected and tested concentrations of the national standards were less than ± 0.4 Log10 IU/m L, which showed high accuracy of the system. Results of the precision, reproducibility and linearity tests showed that the multiple test coefficient of variation(CV) of the same sample was less than 5% for 102-106 IU/m L; and for 30-108 IU/m L, the linear correlation coefficient r2 = 0.99. The TL system detected HBV DNA(A-H) genotypes and there was no cross-contamination during the "checkerboard" test. When compared with the CAP/CTM assay, the two assays showed 100% consistency in both negative and positive sample results(15 negative samples and 185 positive samples). No statistical differences between the two assays in the HBV DNA quantification values were observed(P > 0.05). Correlation analysis indicated a significant correlation between the two assays, r2 = 0.9774. The Bland-Altman plot analysis showed that 98.9% of the positive data were within the 95% acceptable range, and the maximum difference was-0.49.CONCLUSION The TL system has good analytical performance, and exhibits good agreement with the CAP/CTM system in clinical performance.展开更多
DNA and silica-coated magnetic particles entangle and form visible aggregates under chaotropic conditions with a rotating magnetic field, in a manner that enables quantification of DNA by image analysis. As a means of...DNA and silica-coated magnetic particles entangle and form visible aggregates under chaotropic conditions with a rotating magnetic field, in a manner that enables quantification of DNA by image analysis. As a means of exploring the mechanism of this DNA quantitation assay, nanoscale SiO2-coated Fe304 （Fe3O4@SiO2） particles are synthesized via a solvothermal method. Characterization of the particles defines them to be -200 nm in diameter with a large surface area （141.89 m2/g）, possessing superparamagnetic properties and exhibiting high saturation magnetization （38 emu/g）. The synthesized Fe3O4@SiO2 nanoparticles are exploited in the DNA quantification assay and, as predicted, the nanoparticles provide better sensitivity than commercial microscale Dynabeads for quantifying DNA, with a detection limit of 4 kilobase-pair fragments of human DNA. Their utility is proven using nanoparticle DNA quantification to guide efficient polymerase chain reaction （PCR） amplification of short tandem repeat loci for human identification.展开更多
Decellularized organs and tissues are emerging within the field ofregenerative medicine to meet the growing demand for organand tissue transplantation. Quality control of these acellular matrices prior to transplantat...Decellularized organs and tissues are emerging within the field ofregenerative medicine to meet the growing demand for organand tissue transplantation. Quality control of these acellular matrices prior to transplantation is of paramount importance to ensure the absence of an adverse reaction. In particular, thoroughevaluation of the DNA content is essential but also poses technical challenges. Therefore, in this study, we compared differentmethods for quantitative and qualitative evaluation of DNA content in native and decellularized skeletal muscle tissue to identifystrengths and weaknesses for each. Histological analysis revealedthat Feulgen staining is more sensitive and robust than the commonly used hematoxylin–eosin and 40,6-diamidino-2-phenylindole staining for detection of remaining nuclear material.Furthermore, gel electrophoresis allowed to identify the quality and length of remaining DNA fragments. The results of the quantitativeanalysis indicated that direct measurement of DNA content in tissue lysates is preferred over silica-based extraction methods, since thelatter resulted in the loss of small DNA fragments during extraction. Moreover, a weight loss correction factor should be implementedto take into account the impact of the decellularization on the extracellular matrix. With regard to the detection method, the resultsrevealed that a fluorescence-based approach is more accurate than the use of UV/VIS absorbance. Through combination of the proposedmethods, it should be possible to achieve a more standardized evaluation of novel acellular matrices in terms of DNA content and toenhance the predictability of clinical success.展开更多
Background Recent studies suggest that circulating DNA may be a potential tumor marker for lung cancer, but most of these studies are conducted between healthy controls and lung cancer patients, with few or no benign...Background Recent studies suggest that circulating DNA may be a potential tumor marker for lung cancer, but most of these studies are conducted between healthy controls and lung cancer patients, with few or no benign lung disease patients included. The objective of this study was to evaluate the performance of plasma DNA quantification in discriminating lung cancer from the healthy and benign lung disease.Methods Plasma DNA was extracted with a QIAamp DNA Blood Midi kit and quantified by a PicoGreen dsDNA quantitation kit in 44 healthy individuals, 36 benign lung disease patients and 67 lung cancer patients. Discrimination power was evaluated by the receiver operating characteristic curve. Results Plasma DNA values were significantly increased in lung cancer patients, especially in those with metastases, and in benign lung disease patients compared with that in the healthy individuals (P<0.001, respectively). The values in lung cancer patients were significantly increased compared with that in the benign lung disease patients (P<0.001). The area under the curve was 0.96 [95% confidence interval (CI) 0.92-0.99] for the healthy versus lung cancer, 0.73 (95% CI 0.64-0.83) for lung cancer versus benign lung disease, and 0.86 (95% CI 0.80-0.91) for lung cancer versus the healthy and benign lung disease.Conclusions Plasma DNA quantification has a strong power to discriminate lung cancer from the healthy and from the healthy and benign lung disease, less power to discriminate lung cancer from benign lung disease. Plasma DNA quantification may be useful as a screening tool for lung cancer.展开更多
Accurate estimates of DNA quantity are likely to become increasingly important for successful genomic screening of insect populations via recently developed, highly multiplexed genotyping assays and high-throughput se...Accurate estimates of DNA quantity are likely to become increasingly important for successful genomic screening of insect populations via recently developed, highly multiplexed genotyping assays and high-throughput sequencing methods. Here we show that genomic DNA extractions from single Anopheles gambiae Giles using a standard commercial kit-based methodology yield extracts with concentrations below the linear range of spectrophotometric absorbance at 260 nm. Concentrations determined by spectropho- tometry were not reproducible, and are therefore neither accurate nor reliable. However, DNA quantification using a fluorescent nucleic acid stain （PicoGreen） gave highly reproducible concentration estimates, and indicated that, on average, single mosquitoes yielded approximately 300 ng of DNA. Such a total yield is currently insufficient for many highthroughput genome screening applications, necessitating whole genome amplification of all or most individuals in a population prior to genotyping.展开更多
文摘AIM To investigate and compare the analytical and clinical performance of Tian Long automatic hypersensitive hepatitis B virus(HBV) DNA quantification system and Roche CAP/CTM system.METHODS Two hundred blood samples for HBV DNA testing, HBV-DNA negative samples and high-titer HBV-DNA mixture samples were collected and prepared. National standard materials for serum HBV and a worldwide HBV DNA panel were employed for performance verification. The analytical performance, such as limit of detection, limit of quantification, accuracy, precision, reproducibility, linearity, genotype coverage and cross-contamination, was determined using the Tian Long automatic hypersensitive HBV DNA quantification system(TL system). Correlation and Bland-Altman plot analyses were carried out to compare the clinical performance of the TL system assay and the CAP/CTM system. RESULTS The detection limit of the TL system was 10 IU/m L, and its limit of quantification was 30 IU/m L. The differences between the expected and tested concentrations of the national standards were less than ± 0.4 Log10 IU/m L, which showed high accuracy of the system. Results of the precision, reproducibility and linearity tests showed that the multiple test coefficient of variation(CV) of the same sample was less than 5% for 102-106 IU/m L; and for 30-108 IU/m L, the linear correlation coefficient r2 = 0.99. The TL system detected HBV DNA(A-H) genotypes and there was no cross-contamination during the "checkerboard" test. When compared with the CAP/CTM assay, the two assays showed 100% consistency in both negative and positive sample results(15 negative samples and 185 positive samples). No statistical differences between the two assays in the HBV DNA quantification values were observed(P > 0.05). Correlation analysis indicated a significant correlation between the two assays, r2 = 0.9774. The Bland-Altman plot analysis showed that 98.9% of the positive data were within the 95% acceptable range, and the maximum difference was-0.49.CONCLUSION The TL system has good analytical performance, and exhibits good agreement with the CAP/CTM system in clinical performance.
文摘DNA and silica-coated magnetic particles entangle and form visible aggregates under chaotropic conditions with a rotating magnetic field, in a manner that enables quantification of DNA by image analysis. As a means of exploring the mechanism of this DNA quantitation assay, nanoscale SiO2-coated Fe304 （Fe3O4@SiO2） particles are synthesized via a solvothermal method. Characterization of the particles defines them to be -200 nm in diameter with a large surface area （141.89 m2/g）, possessing superparamagnetic properties and exhibiting high saturation magnetization （38 emu/g）. The synthesized Fe3O4@SiO2 nanoparticles are exploited in the DNA quantification assay and, as predicted, the nanoparticles provide better sensitivity than commercial microscale Dynabeads for quantifying DNA, with a detection limit of 4 kilobase-pair fragments of human DNA. Their utility is proven using nanoparticle DNA quantification to guide efficient polymerase chain reaction （PCR） amplification of short tandem repeat loci for human identification.
基金supported by the Research Foundation—Flanders[G0D3620N and 1133520N]。
文摘Decellularized organs and tissues are emerging within the field ofregenerative medicine to meet the growing demand for organand tissue transplantation. Quality control of these acellular matrices prior to transplantation is of paramount importance to ensure the absence of an adverse reaction. In particular, thoroughevaluation of the DNA content is essential but also poses technical challenges. Therefore, in this study, we compared differentmethods for quantitative and qualitative evaluation of DNA content in native and decellularized skeletal muscle tissue to identifystrengths and weaknesses for each. Histological analysis revealedthat Feulgen staining is more sensitive and robust than the commonly used hematoxylin–eosin and 40,6-diamidino-2-phenylindole staining for detection of remaining nuclear material.Furthermore, gel electrophoresis allowed to identify the quality and length of remaining DNA fragments. The results of the quantitativeanalysis indicated that direct measurement of DNA content in tissue lysates is preferred over silica-based extraction methods, since thelatter resulted in the loss of small DNA fragments during extraction. Moreover, a weight loss correction factor should be implementedto take into account the impact of the decellularization on the extracellular matrix. With regard to the detection method, the resultsrevealed that a fluorescence-based approach is more accurate than the use of UV/VIS absorbance. Through combination of the proposedmethods, it should be possible to achieve a more standardized evaluation of novel acellular matrices in terms of DNA content and toenhance the predictability of clinical success.
文摘Background Recent studies suggest that circulating DNA may be a potential tumor marker for lung cancer, but most of these studies are conducted between healthy controls and lung cancer patients, with few or no benign lung disease patients included. The objective of this study was to evaluate the performance of plasma DNA quantification in discriminating lung cancer from the healthy and benign lung disease.Methods Plasma DNA was extracted with a QIAamp DNA Blood Midi kit and quantified by a PicoGreen dsDNA quantitation kit in 44 healthy individuals, 36 benign lung disease patients and 67 lung cancer patients. Discrimination power was evaluated by the receiver operating characteristic curve. Results Plasma DNA values were significantly increased in lung cancer patients, especially in those with metastases, and in benign lung disease patients compared with that in the healthy individuals (P<0.001, respectively). The values in lung cancer patients were significantly increased compared with that in the benign lung disease patients (P<0.001). The area under the curve was 0.96 [95% confidence interval (CI) 0.92-0.99] for the healthy versus lung cancer, 0.73 (95% CI 0.64-0.83) for lung cancer versus benign lung disease, and 0.86 (95% CI 0.80-0.91) for lung cancer versus the healthy and benign lung disease.Conclusions Plasma DNA quantification has a strong power to discriminate lung cancer from the healthy and from the healthy and benign lung disease, less power to discriminate lung cancer from benign lung disease. Plasma DNA quantification may be useful as a screening tool for lung cancer.
文摘Accurate estimates of DNA quantity are likely to become increasingly important for successful genomic screening of insect populations via recently developed, highly multiplexed genotyping assays and high-throughput sequencing methods. Here we show that genomic DNA extractions from single Anopheles gambiae Giles using a standard commercial kit-based methodology yield extracts with concentrations below the linear range of spectrophotometric absorbance at 260 nm. Concentrations determined by spectropho- tometry were not reproducible, and are therefore neither accurate nor reliable. However, DNA quantification using a fluorescent nucleic acid stain （PicoGreen） gave highly reproducible concentration estimates, and indicated that, on average, single mosquitoes yielded approximately 300 ng of DNA. Such a total yield is currently insufficient for many highthroughput genome screening applications, necessitating whole genome amplification of all or most individuals in a population prior to genotyping.
