ABSTRACT
The recent pneumonia outbreak caused by a novel coronavirus (SARS-CoV-2) is posing a great threat to global public health. Therefore, rapid and accurate identification of pathogenic viruses plays a vital role in selecting appropriate treatments, saving people's lives and preventing epidemics. It is important to establish a quick standard diagnostic test for the detection of the infectious disease (COVID-19) to prevent subsequent secondary spread. Polymerase chain reaction (PCR) is regarded as a gold standard test for the molecular diagnosis of viral and bacterial infections with high sensitivity and specificity. Isothermal nucleic acid amplification is considered to be a highly promising candidate method due to its fundamental advantage in quick procedure time at constant temperature without thermocycler opera-tion. A variety of improved or new approaches also have been developed. This review summarizes the currently available detection methods for coronavirus nucleic acid. It is anticipated that this will assist researchers and clinicians in developing better techniques for timely and effective detection of coro-navirus infection.
ABSTRACT
Objective To establish a recombinase aided isothermal amplification (RAA) assay for detection of Clonorchis sinensis. Methods The 18S ribosomal RNA (18S rRNA) sequence of C. sinensis was used as the target sequence, and specific primers and probes were designed, synthesized and screened to establish a rapid fluorescent RAA assay for the detection of C. sinensis. Then, the sensitivity of the fluorescent RAA assay was evaluated using the recombinant plasmids containing various copy numbers of DNA fragments and C. sinensis genomic DNA at various concentrations, and the specificity of the fluorescent RAA as say was evaluated using the genomic DNA of Ascaris lumbricoides, Echinococcus granulosus, Schistosoma japonicum, Ancylostoma duodenale and S. mansoni as templates. DNA samples were extracted from the feces containing C. sinensis eggs and freshwater fish containing metacercaria for the fluorescent RAA assay, and the performance for detection of C. sinensis-infected samples was preliminarily assessed in the field. Results A fluorescent RAA assay for detection of C. sinensis was successfully established, which was feasible for specific amplification of C. sinensis genomic DNA at 39 °C within 20 min. The lowest detection limit was 10 copies/μL if the recombinant plasmid containing various copy numbers of DNA fragments was used as a template, and the lowest detection limit was 3 pg/μL if the C. sinensis genomic DNA at various concentrations served as a template. All detections were negative if the genomic DNA of A. lumbricoides, E. granulosus, S. japonicum, A. duodenale, and S. mansoni was used as templates. In addition, the fluorescent RAA assay showed a high performance for the detection of C. sinensis-infected samples in the field, which successfully detected C. sinensis-infected human and rat fecal samples and Pseudorasbora parva samples. Conclusion A fluorescent RAA assay is successfully established, which is simple, rapid, sensitivity and specific for detection of C. sinensis.
ABSTRACT
Objective To establish a recombinase aided isothermal amplification (RAA) assay for detection of Clonorchis sinensis. Methods The 18S ribosomal RNA (18S rRNA) sequence of C. sinensis was used as the target sequence, and specific primers and probes were designed, synthesized and screened to establish a rapid fluorescent RAA assay for the detection of C. sinensis. Then, the sensitivity of the fluorescent RAA assay was evaluated using the recombinant plasmids containing various copy numbers of DNA fragments and C. sinensis genomic DNA at various concentrations, and the specificity of the fluorescent RAA as say was evaluated using the genomic DNA of Ascaris lumbricoides, Echinococcus granulosus, Schistosoma japonicum, Ancylostoma duodenale and S. mansoni as templates. DNA samples were extracted from the feces containing C. sinensis eggs and freshwater fish containing metacercaria for the fluorescent RAA assay, and the performance for detection of C. sinensis-infected samples was preliminarily assessed in the field. Results A fluorescent RAA assay for detection of C. sinensis was successfully established, which was feasible for specific amplification of C. sinensis genomic DNA at 39 °C within 20 min. The lowest detection limit was 10 copies/μL if the recombinant plasmid containing various copy numbers of DNA fragments was used as a template, and the lowest detection limit was 3 pg/μL if the C. sinensis genomic DNA at various concentrations served as a template. All detections were negative if the genomic DNA of A. lumbricoides, E. granulosus, S. japonicum, A. duodenale, and S. mansoni was used as templates. In addition, the fluorescent RAA assay showed a high performance for the detection of C. sinensis-infected samples in the field, which successfully detected C. sinensis-infected human and rat fecal samples and Pseudorasbora parva samples. Conclusion A fluorescent RAA assay is successfully established, which is simple, rapid, sensitivity and specific for detection of C. sinensis.
ABSTRACT
Accurate identification of varieties is the most important part of quality control of Chinese materia medica (CMM). To find an efficient, convenient, and accurate identification method is the development trend of identification technology of CMM. Compared with the traditional identification method based on phenotypic markers, DNA molecular marker technology is more accurate and reliable, suitable for the identification of closely related species and sample with confusion and multiple sources, but unable to realize the rapid identification due to the limits of the PCR technology, such as high cost, complex procedures, and the drawback of long time. Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification technology, with the advantages of high specificity, high sensitivity, simple, rapid, low cost, etc., become another new technology after PCR to realize the rapid molecular identification of CMM successfully. In this paper, the common isothermal amplification of nucleic acid technology and its application in the study of molecular identification of Chinese herbal medicines were reviewed analysis, to provide a reference for the study of rapid molecular identification system of Chinese herbal medicines.
ABSTRACT
Recombinase polymerase amplification (RPA) is a novel isothermal DNA amplification technology first re-ported in 2006 by Piepenburg et al.This technology has been shown to typically work at temperatures ranging from 25 to 43℃and can detect products within 5-20 min.RPA technology requires little instrumentation for the nucleic acid amplifi-cation reaction and can be performed not only in PCR tubes , but also in simple devices′such as paper .Combined with probe-based detection methods or lateral flow dipstick assay , it can perform quantitative or visual detection respectively . RPA is a technology that is potentially ideal for point-of-care diagnosis and disease prevention and control ,characterized by high sensitivity, high efficiency, high specificity and user-friendliness.This paper introduces the advantages and develop-ment of RPA technology in reaction conditions and product detection ,summarizes the current applications of this technolo-gy,and predicts the trend of application of RPA technology in point-of-care diagnosis and disease prevention and control .