When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses....When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses.Even test samples without any pretreatment can be used as template.This feature suggests that LAMP is superior to PCR in developing point-of-care test strategies.In this study,using Stx1 gene from E.coli as model,we verified that viable cells,dead cells and extracellular DNA could function as template in the LAMP assay.In the incubation at 63℃,viable bacteria in the LAMP reaction mixture lysed completely within 2 min,providing DNA template for nucleic acid amplification.The Stx1 gene in diluted culture medium,spiked tap water,spiked seawater and real seawater all could be detected,with or without the step of DNA extraction.We found that the complex substances in real sample(e.g.natural seawater)exhibited considerable inhibitory effect on the sensitivity of the LAMP assay.These outcomes are meaningful for building a point-of-care strategy by employing the LAMP assay for environmental monitoring,bio-resource surveys,food safety,etc.in particular those based on environmental DNA.展开更多
Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to es...Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to establish a rapid detection method of Pss for the diagnosis and prevention of this disease.In order to robust and accurately diagnose the rice bacterial leaf brown spot disease in the field and laboratory,an assay system for the Pss was developed in this study,and the specific sequence of hrcN was used as the target,based on loop-mediated isothermal amplification(LAMP).The best detection system was MgSO 48 mmol·L^(-1),Bst DNA polymerase 8 U,dNTP 1.4 mmol·L^(-1),the ratio of internal and outer primers was 2:1,the reaction temperature was 63℃,the reaction time was 45 min,and the lowest sensitivity was 104 CFU·mL^(-1).This results provided an accurate and robust method for laboratory and field diagnosis of bacterial leaf brown spot disease of rice.展开更多
The purpose of this study was to establish a method for the rapid detection of infectious pancreatic necrosis virus(IPNV,Jasper serotype)using reverse transcription loop-mediated isothermal amplification(RT-LAMP).Four...The purpose of this study was to establish a method for the rapid detection of infectious pancreatic necrosis virus(IPNV,Jasper serotype)using reverse transcription loop-mediated isothermal amplification(RT-LAMP).Four groups of specific primers were designed,according to the genome sequence of a Chinese IPNV isolate ChRtm213.The results showed that primer set B2 had the best amplification effect.When the final concentration of Mg2+was 6 mmol·L-1,dNTPs were 1 mmol·L-1 and betaine was 0.4 mol·L-1,the reaction could be completed in a 63℃water bath within 60 min.This RT-LAMP assay for the detection of IPNV had no cross-reactivity with infectious hematopoietic necrosis virus,viral hemorrhagic septicemia virus,grass carp reovirus and spring viremia of carp virus.The detection limit was 3.2×10-12 ng·μL-1.The sensitivity of this method was 10-fold higher than that of a previously published RT-LAMP assay for detecting the Spajarup(Sp)serotype of IPNV.This method,aimed at detecting IPNV isolates that were currently prevalent in China,possessed the characteristics of strong specificity,high sensitivity and direct interpretation by the naked eyes.The IPNV RT-LAMP was successfully applied to determine the clinical samples,which indicated the IPNV RT-LAMP assay was suitable for the rapid and large-scale detections of IPNV in China.展开更多
文摘When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses.Even test samples without any pretreatment can be used as template.This feature suggests that LAMP is superior to PCR in developing point-of-care test strategies.In this study,using Stx1 gene from E.coli as model,we verified that viable cells,dead cells and extracellular DNA could function as template in the LAMP assay.In the incubation at 63℃,viable bacteria in the LAMP reaction mixture lysed completely within 2 min,providing DNA template for nucleic acid amplification.The Stx1 gene in diluted culture medium,spiked tap water,spiked seawater and real seawater all could be detected,with or without the step of DNA extraction.We found that the complex substances in real sample(e.g.natural seawater)exhibited considerable inhibitory effect on the sensitivity of the LAMP assay.These outcomes are meaningful for building a point-of-care strategy by employing the LAMP assay for environmental monitoring,bio-resource surveys,food safety,etc.in particular those based on environmental DNA.
基金Supported by the Natural Science Foundation of Heilongjiang Province(Topic C2017032)Heilongjiang Province Applied Technology Research and Development Program(Topic GA19B104)the National Key Research and Development Program(Topic 2018YFD0300105)。
文摘Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to establish a rapid detection method of Pss for the diagnosis and prevention of this disease.In order to robust and accurately diagnose the rice bacterial leaf brown spot disease in the field and laboratory,an assay system for the Pss was developed in this study,and the specific sequence of hrcN was used as the target,based on loop-mediated isothermal amplification(LAMP).The best detection system was MgSO 48 mmol·L^(-1),Bst DNA polymerase 8 U,dNTP 1.4 mmol·L^(-1),the ratio of internal and outer primers was 2:1,the reaction temperature was 63℃,the reaction time was 45 min,and the lowest sensitivity was 104 CFU·mL^(-1).This results provided an accurate and robust method for laboratory and field diagnosis of bacterial leaf brown spot disease of rice.
基金Supported by the National Natural Science Foundation of China(31802345)China Postdoctoral Science Foundation(2018M630893)Heilongjiang Province Postdoctoral Science Foundation(LBH-Z18275)。
文摘The purpose of this study was to establish a method for the rapid detection of infectious pancreatic necrosis virus(IPNV,Jasper serotype)using reverse transcription loop-mediated isothermal amplification(RT-LAMP).Four groups of specific primers were designed,according to the genome sequence of a Chinese IPNV isolate ChRtm213.The results showed that primer set B2 had the best amplification effect.When the final concentration of Mg2+was 6 mmol·L-1,dNTPs were 1 mmol·L-1 and betaine was 0.4 mol·L-1,the reaction could be completed in a 63℃water bath within 60 min.This RT-LAMP assay for the detection of IPNV had no cross-reactivity with infectious hematopoietic necrosis virus,viral hemorrhagic septicemia virus,grass carp reovirus and spring viremia of carp virus.The detection limit was 3.2×10-12 ng·μL-1.The sensitivity of this method was 10-fold higher than that of a previously published RT-LAMP assay for detecting the Spajarup(Sp)serotype of IPNV.This method,aimed at detecting IPNV isolates that were currently prevalent in China,possessed the characteristics of strong specificity,high sensitivity and direct interpretation by the naked eyes.The IPNV RT-LAMP was successfully applied to determine the clinical samples,which indicated the IPNV RT-LAMP assay was suitable for the rapid and large-scale detections of IPNV in China.
