The rapid and accurate detection of peanuts and soybeans allergen is important to the food safety. In this study, Cu-TCPP nanosheet, a kind of ultra-thin metal-organic framework(MOF)was synthesized and applied in loop...The rapid and accurate detection of peanuts and soybeans allergen is important to the food safety. In this study, Cu-TCPP nanosheet, a kind of ultra-thin metal-organic framework(MOF)was synthesized and applied in loop-mediated isothermal amplification(named Cu-TCPP@LAMP), which can inhibit the non-specific amplification by absorbing and precise temperature releasing of single primer. As thus, Cu-TCPP@LAMP can achieve high sensitivity and specific amplification of the target gene. As a result, peanut and soybean allergens genes contained in food were successfully detected with a favorable detection sensitivity(5 ng/μL for peanuts and 10 ng/μL for soybeans)and reliable repeatability(The coefficient of variation was 3.38% for peanuts and 3.33% for soybeans). Moreover, the established method was utilized for detection of several commercial products, and had a high consistency with the standard method. Apart from food allergens, this novel assay can be widely used in other areas, such as pathogen detection, tumor nucleic acid detection and so on.展开更多
The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we esta...The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.展开更多
核酸扩增反应能够在短时间内将特定DNA模板的数量增加106~109倍,显著提高微量核酸检测的灵敏度,但同时扩增产物的遗漏极易造成交叉污染,影响后续检测。扩增反应通过添加荧光染料实现的实时闭管检测,不仅可以避免反应结束后开管操作所导...核酸扩增反应能够在短时间内将特定DNA模板的数量增加106~109倍,显著提高微量核酸检测的灵敏度,但同时扩增产物的遗漏极易造成交叉污染,影响后续检测。扩增反应通过添加荧光染料实现的实时闭管检测,不仅可以避免反应结束后开管操作所导致的交叉污染,还可以通过反应动力学对样品中模板的起始拷贝数定量,以及通过熔解曲线分析鉴别多种靶标来源、进行基因突变扫描和基因分型检测。目前常用的商业化实时检测荧光染料,如SYBR Green I、Eva Green等,其精确结构信息尚未披露,因此只能通过实验“试错法”选取合适染料,无法从根本上获知染料结构和分析性能之间的关系。本文将通过对目前常用的核酸实时检测荧光染料性质和应用进行总结,为其优化选择、设计和开发提供参考依据。展开更多
Enterocytozoon hepatopenaei(EHP)infection has seriously affected prawn culture globally.The symptoms of the infection are not apparent,and traditional detection methods are time consuming and low in accuracy.We develo...Enterocytozoon hepatopenaei(EHP)infection has seriously affected prawn culture globally.The symptoms of the infection are not apparent,and traditional detection methods are time consuming and low in accuracy.We developed a new onsite rapid testing device(size 18.8×16.7×6.6 cm^(3))for EHP based on magnesium pyrophosphate precipitation and facilitated by loop mediated isothermal amplification(LAMP).The design and fabrication of the device enables efficient light absorbance.The device has a highly sensitive detector,high-precision thermal controller,and humanized touch screen.The temperature control precision of the device is 0.2-0.3℃ at 60℃,63℃,and 65℃.The coefficients of variation values(CVV)of the luminous power in one channel at light on and off were found to be 0.0097 and 0.0014,respectively,within 1 h.The CVV of the background,luminous power,and values of eight PCR tubes filled with pure water were all less than 5%.In the EHP experiment,eight samples(including seven positive and one negative)confirmed the effectiveness of the device,and four positive and four negative samples verified whether cross-contamination exists.Among them,the rise time of the curve was about 15 min.These results assert that the developed device exhibits enhanced stability and uniformity and has excellent performance with high sensitivity,good specificity,and low testing time.Moreover,the optimal and minimum absorbance range was 555-655 nm for monitoring the production of LAMP.展开更多
基金the Science and Technology Joint Project of the Yangtze River Delta (19395810100)Shanghai Agriculture Project (19391901500)+2 种基金the National Key Research and Development Program of China (2016YFD0501101)the Shanghai Science and Technology Innovation Foundation (19441903900 and 19XD1433000)Project of National Natural Science Foundation of China (82003705)。
文摘The rapid and accurate detection of peanuts and soybeans allergen is important to the food safety. In this study, Cu-TCPP nanosheet, a kind of ultra-thin metal-organic framework(MOF)was synthesized and applied in loop-mediated isothermal amplification(named Cu-TCPP@LAMP), which can inhibit the non-specific amplification by absorbing and precise temperature releasing of single primer. As thus, Cu-TCPP@LAMP can achieve high sensitivity and specific amplification of the target gene. As a result, peanut and soybean allergens genes contained in food were successfully detected with a favorable detection sensitivity(5 ng/μL for peanuts and 10 ng/μL for soybeans)and reliable repeatability(The coefficient of variation was 3.38% for peanuts and 3.33% for soybeans). Moreover, the established method was utilized for detection of several commercial products, and had a high consistency with the standard method. Apart from food allergens, this novel assay can be widely used in other areas, such as pathogen detection, tumor nucleic acid detection and so on.
基金supported by the National Natural Science Foundation of China (Nos. 31470271 and 81730110)Guangzhou Science and Technology Program key projects (No. 201803040006)
文摘The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.
文摘核酸扩增反应能够在短时间内将特定DNA模板的数量增加106~109倍,显著提高微量核酸检测的灵敏度,但同时扩增产物的遗漏极易造成交叉污染,影响后续检测。扩增反应通过添加荧光染料实现的实时闭管检测,不仅可以避免反应结束后开管操作所导致的交叉污染,还可以通过反应动力学对样品中模板的起始拷贝数定量,以及通过熔解曲线分析鉴别多种靶标来源、进行基因突变扫描和基因分型检测。目前常用的商业化实时检测荧光染料,如SYBR Green I、Eva Green等,其精确结构信息尚未披露,因此只能通过实验“试错法”选取合适染料,无法从根本上获知染料结构和分析性能之间的关系。本文将通过对目前常用的核酸实时检测荧光染料性质和应用进行总结,为其优化选择、设计和开发提供参考依据。
基金supported by the grant from the National Natural Science Foundation of China(Nos.61901168,61971187,61871180,82002405)Hunan Key Research and Development Program(No.2021SK2003)+1 种基金Zhuzhou Innovative City Construction Project(No.2020-020)China Postdoctoral Science Foundation(No.2018M630498)。
文摘Enterocytozoon hepatopenaei(EHP)infection has seriously affected prawn culture globally.The symptoms of the infection are not apparent,and traditional detection methods are time consuming and low in accuracy.We developed a new onsite rapid testing device(size 18.8×16.7×6.6 cm^(3))for EHP based on magnesium pyrophosphate precipitation and facilitated by loop mediated isothermal amplification(LAMP).The design and fabrication of the device enables efficient light absorbance.The device has a highly sensitive detector,high-precision thermal controller,and humanized touch screen.The temperature control precision of the device is 0.2-0.3℃ at 60℃,63℃,and 65℃.The coefficients of variation values(CVV)of the luminous power in one channel at light on and off were found to be 0.0097 and 0.0014,respectively,within 1 h.The CVV of the background,luminous power,and values of eight PCR tubes filled with pure water were all less than 5%.In the EHP experiment,eight samples(including seven positive and one negative)confirmed the effectiveness of the device,and four positive and four negative samples verified whether cross-contamination exists.Among them,the rise time of the curve was about 15 min.These results assert that the developed device exhibits enhanced stability and uniformity and has excellent performance with high sensitivity,good specificity,and low testing time.Moreover,the optimal and minimum absorbance range was 555-655 nm for monitoring the production of LAMP.
