Introduction:Fluorescent probe-based recombinase aided amplification(RAA)offers the advantages of rapidity and simplicity but is limited by the requirement for complex and lengthy probe design,restricting its widespre...Introduction:Fluorescent probe-based recombinase aided amplification(RAA)offers the advantages of rapidity and simplicity but is limited by the requirement for complex and lengthy probe design,restricting its widespread application.Methods:A novel EvaGreen dye-based RAA(EvaGreen-RAA)assay utilizing self-avoiding molecular recognition system(SAMRS)primers was developed for the detection of Pseudomonas fluorescens(PF)and Bacillus cereus(BC)in milk.Conventional RAA was used as a reference method.Sensitivity was evaluated using nucleic acids from recombinant plasmids and simulated milk specimens.Additionally,a dual EvaGreen-RAA assay was investigated for simultaneous detection of mixed BC and PF in simulated milk specimens.Results:The EvaGreen-RAA demonstrated superior sensitivity compared to conventional RAA,with detection limits of 1 copy/μL versus 10 copies/μL for both BC and PF plasmids,respectively.In simulated milk specimens,EvaGreen-RAA detected BC and PF at concentrations of 100 CFU/mL and 200 CFU/mL,respectively,compared to 400 CFU/mL and 600 CFU/mL for conventional RAA.The dual EvaGreen-RAA assay successfully detected mixed BC and PF in simulated milk specimens at concentrations of 200 CFU/mL for each pathogen.Conclusion:The EvaGreen-RAA assay demonstrated significant advantages in terms of simplicity and enhanced sensitivity compared to fluorescent probe-based RAA,offering a novel approach for developing multiplex pathogen detection systems using melting curve analysis.展开更多
Exactly how the immune system discriminates between all environmental antigens to which it reacts vs. all selfantigens to which it does not, is a principal unanswered question in immunology. As set forth in this revie...Exactly how the immune system discriminates between all environmental antigens to which it reacts vs. all selfantigens to which it does not, is a principal unanswered question in immunology. As set forth in this review, because of the advances in our understanding of the immune system that have occurred in the last 50 years, for the first time it is possible to formulate a new theory, termed the ＂Quantal Theory of Immunity＂, which reduces the problem from the immune system as a whole, to the individual cells comprising the system, and finally to a molecular explanation as to how the system behaves as it does.展开更多
基金Supported by Shandong Province Key Research and Development Plan(Major Scientific and Technological Innovation Project,2023CXGC010711)the National Key R&D Program of China(2021YFC2301102)the National Natural Science Foundation of China(82202593,U23A20106).
文摘Introduction:Fluorescent probe-based recombinase aided amplification(RAA)offers the advantages of rapidity and simplicity but is limited by the requirement for complex and lengthy probe design,restricting its widespread application.Methods:A novel EvaGreen dye-based RAA(EvaGreen-RAA)assay utilizing self-avoiding molecular recognition system(SAMRS)primers was developed for the detection of Pseudomonas fluorescens(PF)and Bacillus cereus(BC)in milk.Conventional RAA was used as a reference method.Sensitivity was evaluated using nucleic acids from recombinant plasmids and simulated milk specimens.Additionally,a dual EvaGreen-RAA assay was investigated for simultaneous detection of mixed BC and PF in simulated milk specimens.Results:The EvaGreen-RAA demonstrated superior sensitivity compared to conventional RAA,with detection limits of 1 copy/μL versus 10 copies/μL for both BC and PF plasmids,respectively.In simulated milk specimens,EvaGreen-RAA detected BC and PF at concentrations of 100 CFU/mL and 200 CFU/mL,respectively,compared to 400 CFU/mL and 600 CFU/mL for conventional RAA.The dual EvaGreen-RAA assay successfully detected mixed BC and PF in simulated milk specimens at concentrations of 200 CFU/mL for each pathogen.Conclusion:The EvaGreen-RAA assay demonstrated significant advantages in terms of simplicity and enhanced sensitivity compared to fluorescent probe-based RAA,offering a novel approach for developing multiplex pathogen detection systems using melting curve analysis.
文摘Exactly how the immune system discriminates between all environmental antigens to which it reacts vs. all selfantigens to which it does not, is a principal unanswered question in immunology. As set forth in this review, because of the advances in our understanding of the immune system that have occurred in the last 50 years, for the first time it is possible to formulate a new theory, termed the ＂Quantal Theory of Immunity＂, which reduces the problem from the immune system as a whole, to the individual cells comprising the system, and finally to a molecular explanation as to how the system behaves as it does.
