Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International ...Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)guildline Q5A(R2)from September 2022 highlights the inclusion of viral vector-based gene therapy products in safety discussions,emphasizing controls in material sourcing,testing,and viral clearance[1].Detecting adventitious virus contamination is complex due to the unique characteristics of gene therapy products and the limitations of routine testing methods.The US Food and Drug Administration(FDA)recommends incorporating routine and specific virus detection methods,including those outlined in various pharmacopeias.Existing control methods have limitations,prompting the need for highly sensitive and broad-spectrum detection approaches.Unlike traditional biological products,gene therapy products primarily consist of live viruses,necessitating methods that distinguish between the main virus and adventitious viruses.Current virus detection techniques,such as polymerase chain reaction(PCR),sequencing,mass spectrometry,and DNA microarrays[2e4],have their drawbacks.展开更多
Rice blast is one of the important diseases in major rice producing areas of China. The main blast resistance genes Pi-ta and Pi-b showed broad-spectrum and durable resistance to rice blast in many rice growing areas ...Rice blast is one of the important diseases in major rice producing areas of China. The main blast resistance genes Pi-ta and Pi-b showed broad-spectrum and durable resistance to rice blast in many rice growing areas of China, which have been widely utilized in rice breeding and commercial production. In this study, on the basis of detection and verification of the genotypes of 22 rice varieties har- boring known blast resistance genes （Pi-ta and Pi-b） and blast susceptibility genes （pi-ta and pi-b）, two multiple PCR systems for these genes were established by us- ing the functional markers of blast resistance genes Pi-ta and Pi-b as well as blast susceptibility genes pi-ta and pi-b, respectively. Specifically, multiple PCR system I could simultaneously detect blast resistance genes Pi-ta and Pi-b, while system II could detect simultaneously blast susceptibility genes pi-ta and pi-b. In addition, the genotypes of 336 high generation breeding materials were detected with these two multiple PCR systems. The results were highly consistent with those of conventional single mark detection, indicating that these two multiplex PCR systems were stable, reliable and time-saving. The established multiplex PCR systems may serve as a rapid and efficient method to identify and screen rice germplasm resources and can be applied in marker-assisted selection to polymerize multiple genes for blast resis- tance in rice breeding.展开更多
[Objective] This study aimed to establish a multiplex PCR system for de- tecting transgenic ingredients from Citrus. [Method] Based on the pBI121 plasmid sequences published in GenBank and actin gene sequence of Citru...[Objective] This study aimed to establish a multiplex PCR system for de- tecting transgenic ingredients from Citrus. [Method] Based on the pBI121 plasmid sequences published in GenBank and actin gene sequence of Citrus, the primers specific to CaMV35S promoter, NOS promoter, NOS terminator and actin gene were designed, to establish a multiple PCR system which could detect four types of sequences. In addition, orthogonal tests were performed to determine the optimal concentrations of all the components in PCR reaction system, as well as the optimal PCR cycle parameters. [Result] The optimal PCR reaction system should contain 2.5μl of 10xPCR buffer, 2.0μl of MgCI2 （25 mmol/L）, 2.0 μl of dNTP mixture （2.5 mmol/L of each dNTP）, 1.0 μl of actin gene primers （10μmol/L）, 1.0μl of 35S promoter primers （10 μmol/L）, 1.5 μl of NOS promoter primers （10 μmol/L） and 0.5 μl of NOS terminator primers （10μmol/L）, 0.1 μg of template DNA, 1.25 U of Taq DNA polymerase; ddH20 was added to the total reaction system of 25μl. The PCR reaction program consisted of pre-denaturing at 94℃ for 5 min; 31 cycles of denaturing at 94℃ for 30 s, annealing at 64.1℃ for 45 s and extension at 72℃ for 50 s; final extension at 72℃ for 10 min. The reaction system optimized with the orthogonal tests could detect as less as 0.1% transgenic component in the tested samples. [Conclusion] The MPCR detection system established in this study can meet the requirements in theory for detecting the genetically modified ingredients in Citrus or the deep-processed products.展开更多
[Objective]The aim was to establish the multiplex PCR method for three virus of potato：PVA（potato virus A）,TMV（Tobacco mosaic virus）and PVY（potato virus Y）.[Method]According to the PVA,TMV and PVY sequences ava...[Objective]The aim was to establish the multiplex PCR method for three virus of potato：PVA（potato virus A）,TMV（Tobacco mosaic virus）and PVY（potato virus Y）.[Method]According to the PVA,TMV and PVY sequences available in GenBank,pairs of primer were designed for establishing a multiplex PCR method,and constructing recombinant plasmid of target genes by PCR amplified of three viruses as reference standard simple to be used in sensitivity test;PVX（Potato virus X）,PVM（Potato virus M）,PVS（Potato virus S）,PVV（Potato virus V）and CMV（Cucumber mosaic virus）were used to carry out the specificity test and detection of 11 samples which were suspected of virus infected.[Result]The detection limit for PVA,TMV and PVY was 14,14 and 14 copies/ml,respectively.No cross-reactivity was observed with other viruses.Seven of 11 samples were infected by three viruses.[Conclusion]The multiplex PCR for PVA,TMV,PVY three viruses of potato was established successfully,which had provided basis for the detection technology of potato virus.展开更多
Objectives: To compare multiplex fluorescent PCRwith serum type-specific antibody detection in thediagnosis of herpes simplex virus (HSV) infection andto evaluate its significance in the diagnosis of genitalherpes.Met...Objectives: To compare multiplex fluorescent PCRwith serum type-specific antibody detection in thediagnosis of herpes simplex virus (HSV) infection andto evaluate its significance in the diagnosis of genitalherpes.Methods: We detected HSV infection in 121 speci-mens collected from patients with genital herpesusing both multiplex fluorescent PCR and serum type-specific antibody detection. HSV viral isolation wasused as the standard control.Results: When compared with the viral isolation, thesensitivity and specificity for multiplex fluorescentPCR were 100% and 88.89%, respectively afterdiscrepant analysis. The sensitivity and specificity fortype-specific antibody detection was 77.68 % and77.78 %, respectively. However, the type-specificantibody detected HSV in two asymptomatic patientswhile the multiplex fluorescent PCR couldn’t detectany HSV DNA from those specimens.Conclusions: Multiplex fluorescent PCR is a verysensitive and specific method for detection and typingof HSV in the lesion of genital herpes, it failed todetect HSV DNA from the asymptomatic patients.Serum type-specific antibody detection was a lesssensitive and specific test but could detect the specificantibody from some asymptomatic patients. Thecombination of these two techniques would allow rapid,sensitive and accurate detection and typing of HSVand help clinical diagnosis and epidemiologic survey-ing of genital herpes.展开更多
In an effort to simplify the procedure and to reduce the cost of fluorescence SSR analysis, the conditions of the multiplex PCR and the multiplex gel electrophoresis were optimized in the genetic analysis of sunflower...In an effort to simplify the procedure and to reduce the cost of fluorescence SSR analysis, the conditions of the multiplex PCR and the multiplex gel electrophoresis were optimized in the genetic analysis of sunflower (Helianthus annuus L.) inbred lines. Results indicated that factors for a successful multiplex PCR assay were related to the cycling touchdown annealing temperature, the balance of primer concentration at the various loci, the concentration of PCR buffer and the Taq DNA polymerase. Based on the optimization, a tailed primer strategy was outlined, and the effective ways were proposed to overcome the troubleshootings commonly encountered in the multiplex PCR and the multiplex gel electrophoresis.展开更多
In this paper, we developed a rapid and accurate method for the detection of Vibrio parahaemolyticus strains, using multiplex PCR and DNA--DNA hybridization. Multiplex PCR was used to simultaneously amplify three diag...In this paper, we developed a rapid and accurate method for the detection of Vibrio parahaemolyticus strains, using multiplex PCR and DNA--DNA hybridization. Multiplex PCR was used to simultaneously amplify three diagnostic genes （tlh, tdh andfla） that serve as molecular markers of V. parahaemolyticus. Biotinylated PCR products were hybridized to primers immobilized on a microarray, and detected by chemiluminesce with avidin-conjugated alkaline phosphatase. With this method, forty-five samples were tested. Eight known virulent strains （tlh＋/tdh＋/fla＋） and four known avirulent strains （tlh＋/tdh /fla＋） of the V. parahaemolyticus were successfully detected, and no non-specific hybridization and cross-hybridization reaction were found from fifteen closely-related strains （tlh-/tdh-/fla＋） of the Vibrio spp. In addition, all the other eighteen strains of non-Vibrio bacteria （tlh-/tdh /fla-） gave negative results. The DNA microarray successfully distinguished V. parahaemolyticus from other Vibrio spp. The results demonstrated that this was an efficient and robust method for identifying virulent strains of V. parahaemolyticus.展开更多
Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were...Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were used to amplify the target genes in genetically modified （GM） soybean. Seventeen capture probes （PCR products） and 17 pairs of corresponding primers were designed according to the genetic characteristics of Rroundup Ready soybean （GTS40-3-2）, maize （MonS10, Nk603, GA21）, canola （T45, MS1/RF1）, and rice （SCK） in many identified GM crops. All of the probes were categorized and identified as species-specific probes. One negative probe and one positive control probe were used to assess the efficiency of all reactions, and therefore eliminate any false positive and negative results. After multiplex PCR reaction, amplicons were adulterated with Cy5-dUTP and hybridized with DNA microarray. The array was then scanned to display the specific hybridization signals of target genes. The assay was applied to the analysis of sample of certified transgenic soybean （Roundup Ready GTS40-3-2） and canola （MS1/RF1）. Results A combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS 1/RF1 canola with a great specificity and reliability. Reliable identification of genetic characteristics of Roundup Ready of GM soybean from genetically modified crops was achieved at 0.5% transgenic events, indicating a high sensitivity. Conclusion A combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.展开更多
基金financially supported by Beijing Municipal Science&Technology Commission,China(Grant No.:Z221100007922015)Youth Development Research Foundation of National Institutes for Food and Drug Control,China(Grant No.:2020B1).
文摘Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)guildline Q5A(R2)from September 2022 highlights the inclusion of viral vector-based gene therapy products in safety discussions,emphasizing controls in material sourcing,testing,and viral clearance[1].Detecting adventitious virus contamination is complex due to the unique characteristics of gene therapy products and the limitations of routine testing methods.The US Food and Drug Administration(FDA)recommends incorporating routine and specific virus detection methods,including those outlined in various pharmacopeias.Existing control methods have limitations,prompting the need for highly sensitive and broad-spectrum detection approaches.Unlike traditional biological products,gene therapy products primarily consist of live viruses,necessitating methods that distinguish between the main virus and adventitious viruses.Current virus detection techniques,such as polymerase chain reaction(PCR),sequencing,mass spectrometry,and DNA microarrays[2e4],have their drawbacks.
基金Supported by Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province[CX(12)1003]Science and Technology Support Program of Jiangsu Province(BE2013301)Special Fund for the Construction of Modern Agriculture Industry System of China(CARS-01-47)~~
文摘Rice blast is one of the important diseases in major rice producing areas of China. The main blast resistance genes Pi-ta and Pi-b showed broad-spectrum and durable resistance to rice blast in many rice growing areas of China, which have been widely utilized in rice breeding and commercial production. In this study, on the basis of detection and verification of the genotypes of 22 rice varieties har- boring known blast resistance genes （Pi-ta and Pi-b） and blast susceptibility genes （pi-ta and pi-b）, two multiple PCR systems for these genes were established by us- ing the functional markers of blast resistance genes Pi-ta and Pi-b as well as blast susceptibility genes pi-ta and pi-b, respectively. Specifically, multiple PCR system I could simultaneously detect blast resistance genes Pi-ta and Pi-b, while system II could detect simultaneously blast susceptibility genes pi-ta and pi-b. In addition, the genotypes of 336 high generation breeding materials were detected with these two multiple PCR systems. The results were highly consistent with those of conventional single mark detection, indicating that these two multiplex PCR systems were stable, reliable and time-saving. The established multiplex PCR systems may serve as a rapid and efficient method to identify and screen rice germplasm resources and can be applied in marker-assisted selection to polymerize multiple genes for blast resis- tance in rice breeding.
基金Supported by the Special Fund for Key Laboratories of Chongqing (CSTC)National Technology Research and Development Program of Ministry of Science and Technology for Countryside Field (863 Program,2011AA100205)+1 种基金Special Fund for Agro-scientific Research in the Public Interest of Ministry of Agriculture of China(201003067)Key Science and Technology Research Program of Ministry of Education of China (109131)~~
文摘[Objective] This study aimed to establish a multiplex PCR system for de- tecting transgenic ingredients from Citrus. [Method] Based on the pBI121 plasmid sequences published in GenBank and actin gene sequence of Citrus, the primers specific to CaMV35S promoter, NOS promoter, NOS terminator and actin gene were designed, to establish a multiple PCR system which could detect four types of sequences. In addition, orthogonal tests were performed to determine the optimal concentrations of all the components in PCR reaction system, as well as the optimal PCR cycle parameters. [Result] The optimal PCR reaction system should contain 2.5μl of 10xPCR buffer, 2.0μl of MgCI2 （25 mmol/L）, 2.0 μl of dNTP mixture （2.5 mmol/L of each dNTP）, 1.0 μl of actin gene primers （10μmol/L）, 1.0μl of 35S promoter primers （10 μmol/L）, 1.5 μl of NOS promoter primers （10 μmol/L） and 0.5 μl of NOS terminator primers （10μmol/L）, 0.1 μg of template DNA, 1.25 U of Taq DNA polymerase; ddH20 was added to the total reaction system of 25μl. The PCR reaction program consisted of pre-denaturing at 94℃ for 5 min; 31 cycles of denaturing at 94℃ for 30 s, annealing at 64.1℃ for 45 s and extension at 72℃ for 50 s; final extension at 72℃ for 10 min. The reaction system optimized with the orthogonal tests could detect as less as 0.1% transgenic component in the tested samples. [Conclusion] The MPCR detection system established in this study can meet the requirements in theory for detecting the genetically modified ingredients in Citrus or the deep-processed products.
文摘[Objective]The aim was to establish the multiplex PCR method for three virus of potato：PVA（potato virus A）,TMV（Tobacco mosaic virus）and PVY（potato virus Y）.[Method]According to the PVA,TMV and PVY sequences available in GenBank,pairs of primer were designed for establishing a multiplex PCR method,and constructing recombinant plasmid of target genes by PCR amplified of three viruses as reference standard simple to be used in sensitivity test;PVX（Potato virus X）,PVM（Potato virus M）,PVS（Potato virus S）,PVV（Potato virus V）and CMV（Cucumber mosaic virus）were used to carry out the specificity test and detection of 11 samples which were suspected of virus infected.[Result]The detection limit for PVA,TMV and PVY was 14,14 and 14 copies/ml,respectively.No cross-reactivity was observed with other viruses.Seven of 11 samples were infected by three viruses.[Conclusion]The multiplex PCR for PVA,TMV,PVY three viruses of potato was established successfully,which had provided basis for the detection technology of potato virus.
文摘Objectives: To compare multiplex fluorescent PCRwith serum type-specific antibody detection in thediagnosis of herpes simplex virus (HSV) infection andto evaluate its significance in the diagnosis of genitalherpes.Methods: We detected HSV infection in 121 speci-mens collected from patients with genital herpesusing both multiplex fluorescent PCR and serum type-specific antibody detection. HSV viral isolation wasused as the standard control.Results: When compared with the viral isolation, thesensitivity and specificity for multiplex fluorescentPCR were 100% and 88.89%, respectively afterdiscrepant analysis. The sensitivity and specificity fortype-specific antibody detection was 77.68 % and77.78 %, respectively. However, the type-specificantibody detected HSV in two asymptomatic patientswhile the multiplex fluorescent PCR couldn’t detectany HSV DNA from those specimens.Conclusions: Multiplex fluorescent PCR is a verysensitive and specific method for detection and typingof HSV in the lesion of genital herpes, it failed todetect HSV DNA from the asymptomatic patients.Serum type-specific antibody detection was a lesssensitive and specific test but could detect the specificantibody from some asymptomatic patients. Thecombination of these two techniques would allow rapid,sensitive and accurate detection and typing of HSVand help clinical diagnosis and epidemiologic survey-ing of genital herpes.
文摘In an effort to simplify the procedure and to reduce the cost of fluorescence SSR analysis, the conditions of the multiplex PCR and the multiplex gel electrophoresis were optimized in the genetic analysis of sunflower (Helianthus annuus L.) inbred lines. Results indicated that factors for a successful multiplex PCR assay were related to the cycling touchdown annealing temperature, the balance of primer concentration at the various loci, the concentration of PCR buffer and the Taq DNA polymerase. Based on the optimization, a tailed primer strategy was outlined, and the effective ways were proposed to overcome the troubleshootings commonly encountered in the multiplex PCR and the multiplex gel electrophoresis.
基金financial supports from National High Technology Research and Development Program of China(No.2007AA10Z430)National Natural Science Foundation of China(No.30700535)Program for New Century Excellent Talents in Fujian Province University,and Fok Ying Tong Education Foundation(No.111032)
文摘In this paper, we developed a rapid and accurate method for the detection of Vibrio parahaemolyticus strains, using multiplex PCR and DNA--DNA hybridization. Multiplex PCR was used to simultaneously amplify three diagnostic genes （tlh, tdh andfla） that serve as molecular markers of V. parahaemolyticus. Biotinylated PCR products were hybridized to primers immobilized on a microarray, and detected by chemiluminesce with avidin-conjugated alkaline phosphatase. With this method, forty-five samples were tested. Eight known virulent strains （tlh＋/tdh＋/fla＋） and four known avirulent strains （tlh＋/tdh /fla＋） of the V. parahaemolyticus were successfully detected, and no non-specific hybridization and cross-hybridization reaction were found from fifteen closely-related strains （tlh-/tdh-/fla＋） of the Vibrio spp. In addition, all the other eighteen strains of non-Vibrio bacteria （tlh-/tdh /fla-） gave negative results. The DNA microarray successfully distinguished V. parahaemolyticus from other Vibrio spp. The results demonstrated that this was an efficient and robust method for identifying virulent strains of V. parahaemolyticus.
基金National Basic Research Program of China (No. 2001CB109001)National High-Tech Research Program of China (No. 2002AA212041)
文摘Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were used to amplify the target genes in genetically modified （GM） soybean. Seventeen capture probes （PCR products） and 17 pairs of corresponding primers were designed according to the genetic characteristics of Rroundup Ready soybean （GTS40-3-2）, maize （MonS10, Nk603, GA21）, canola （T45, MS1/RF1）, and rice （SCK） in many identified GM crops. All of the probes were categorized and identified as species-specific probes. One negative probe and one positive control probe were used to assess the efficiency of all reactions, and therefore eliminate any false positive and negative results. After multiplex PCR reaction, amplicons were adulterated with Cy5-dUTP and hybridized with DNA microarray. The array was then scanned to display the specific hybridization signals of target genes. The assay was applied to the analysis of sample of certified transgenic soybean （Roundup Ready GTS40-3-2） and canola （MS1/RF1）. Results A combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS 1/RF1 canola with a great specificity and reliability. Reliable identification of genetic characteristics of Roundup Ready of GM soybean from genetically modified crops was achieved at 0.5% transgenic events, indicating a high sensitivity. Conclusion A combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.
