In this study,the DNA probe pPF14 was nonradioactively labelled by sulfo-modifica-tion,and used in a dot blot hybridization assay for detection of P.falciparum.The resultsshowed that the sulfoprobe successfully detect...In this study,the DNA probe pPF14 was nonradioactively labelled by sulfo-modifica-tion,and used in a dot blot hybridization assay for detection of P.falciparum.The resultsshowed that the sulfoprobe successfully detected 25pg purified DNA and 0.001% parasitemia ofcultured P.falciparum,and did not react with human leukocyte DNA.In the study of 179clinical blood samples of malaria patients from Yunnan province,the DNA probe results corre-lated well with blood smear ones.Of 107 P.falciparum samples determined by microscope ex-amination,99 were positive by sulfoprobe (92.5%);Of 72 P.vivax samples,1 was crosslyreacted;no cross reactions were found with any of 48 normal blood samples.It is indicated thatsulfoprobe may be useful in specific diagnosis and epidemiological investigation of P.falciparuminfection.展开更多
To screen species-specific DNA probes for identification of Fallopia muhiflora, the genomic DNA (gDNA) suppression subtraction hybridization (SSH) between F. muhiflora and F. muhiflora var. ciliinervis was firstly...To screen species-specific DNA probes for identification of Fallopia muhiflora, the genomic DNA (gDNA) suppression subtraction hybridization (SSH) between F. muhiflora and F. muhiflora var. ciliinervis was firstly performed. The obtained differential gDNA fragments by SSH were then hybridized with gDNA ar- rays consisting of multiple whole genomes of several species (adulterants and/or closely related species of F. muhiflora) and four differential fragments were screened uniquely representing F. muhiflora, which could be used as F. muhiflora species-specific probes. The screened DNA probes were tested by reverse dot blot hybridization and the results demonstrated that these probes could be used reliably to identify F, muhiflora. The species-specific DNA probes obtained in this study exhibited broad application prospects in the preparation of gene chips for identifying Chinese traditional medicines and the authentication of germplasm re- sources and crude drugs of F. muhiflora.展开更多
A commercially available non—radioactive DNA labelling kit "enhanced chemiluminescence"(ECL) was evaluated for the diagnosis of falciparum malaria. The results showed that ECL labeled probe successfully det...A commercially available non—radioactive DNA labelling kit "enhanced chemiluminescence"(ECL) was evaluated for the diagnosis of falciparum malaria. The results showed that ECL labeled probe successfully detected as little as 25 pg. Purified DNA of 0.001% parasitemia of cultured Plasmodium falciparum and did not react with human展开更多
Subject Code:B05 With the support by the National Natural Science Foundation of China and the US National Institutes of Health,a team led by Dr.Tan Weihong(谭蔚泓)at Hunan University and the University of Florida repo...Subject Code:B05 With the support by the National Natural Science Foundation of China and the US National Institutes of Health,a team led by Dr.Tan Weihong(谭蔚泓)at Hunan University and the University of Florida reported a new DNA probe for studying cell membrane interactions,which was recently published展开更多
AIM: To develop a real-time PCR for detecting hepatitis B virus-(HBV) DNA based on TaqMan technology using a new MGB probe.METHODS: Plasmid containing the sequence of X gene (1414-1744 nt) was constructed as HBV-DNA s...AIM: To develop a real-time PCR for detecting hepatitis B virus-(HBV) DNA based on TaqMan technology using a new MGB probe.METHODS: Plasmid containing the sequence of X gene (1414-1744 nt) was constructed as HBV-DNA standard for quantitative analysis. A TaqMan-MGB probe between primers for amplification was designed to detect PCR products. The interested sequence contained in the plasmid and in clinical specimens was quantitatively measured.RESULTS: The detection limit of the assay for HBV DNA was 1 genome equivalent per reaction. A linear standard curve was obtained between 100 and 109 DNA copies/reaction (r>0.990). None of the negative control samples showed false-positive reactions in duplicate. HBV DNA was detected in 100% (50/50) of HBV patients with HbeAg, and in 72.0% (36/50) with HBsAg, HBeAb and HBcAb. The coefficient of variation for both intra- and inter-experimental variability demonstrated high reproducibility and accuracy.CONCLUSION: Real-time PCR based on TaqMan-MGB probe technology is an excellent method for detection of HBV DNA.展开更多
Sterically spacing and locating functional matters at the nanoscale exert critical effects on their application,especially for the fluorescence probes whose aggregation causes emission quenching.Here we achieved a hie...Sterically spacing and locating functional matters at the nanoscale exert critical effects on their application,especially for the fluorescence probes whose aggregation causes emission quenching.Here we achieved a hierarchical spacing strategy of DNA fluorescence probes for ion detection via locating them separately on rod-like cellulose nanocrystals(CNCs)and further isolating CNCs by pre-grafting long molecular chains.Controlling chemical structure of CNC and location degree could adjust the interspace of DNA probes(with a molecular length of ca.3.6 nm)in a range of 3.5-6.5 nm with a gradient about 0.2 nm.A length up to micrometer scale of the CNC nanorods was necessary to provide DNA probes with well-separated grafting locations and enough freedom,which brought a vast linear detection range from 10 nmol/L to 5 μmol/L of Hg^2+ concentration.The abundant reactive sites on CNC allowed a grafting pre-location of poly(tert-butyl acrylate)(PtBA)to promote the isolation of DNA probes.Controlled radical polymerization was employed to adj ust the length of PtBA molecular chains,which increased the linear sensitivity coefficient of Hg^2+ detection by ca.2.5 times.This hierarchical nanoscale spacing concept based on chemical design can hopefully cond uce to the development of biosensor and medical diagnosis.A hierarchical spacing strategy was applied to separate DNA fluorescent probes on CNCs and detect ion concentration linearly.The first-level spacing was to locate probes uniformly on CNCs,obtaining a wide linear range;and the second-level spacing was to isolate CNCs with polymer,obtaining an increased linear coefficient.展开更多
A new carbazole tricationic salt,4,4'-(1E,1'E)-2,2'-(9-(2-(1-(2-hydroxyethyl)pyridinium-4-yl)ethyl)-9H-carbazole-3,6-diyl) bis(ethane-2,1-diyl) bis(1-(2-hydroxyethyl)pyridinium) iodide (THEPC) was synthesi...A new carbazole tricationic salt,4,4'-(1E,1'E)-2,2'-(9-(2-(1-(2-hydroxyethyl)pyridinium-4-yl)ethyl)-9H-carbazole-3,6-diyl) bis(ethane-2,1-diyl) bis(1-(2-hydroxyethyl)pyridinium) iodide (THEPC) was synthesized. Photophysical experiments have shown that THEPC has large two-photon excited fluorescence action cross-sections (33 GM in the presence of DNA),which ranks THEPC as a good biological fluorophore. The results from electronic absorption,circle dichroism and single-/two-photon fluorescence emission spectra suggest that THEPC can strongly bind to DNA,with an intrinsic binding constant of 5.79 × 106 L mol-1. THEPC has better photostability under one-or two-photon excitation conditions. Finally,the staining photos from two-photon fluorescence microscopy (TPM) show that THEPC can exclusively label the nucleus with high contrast and without image distortion. These remarkable properties and optimized imaging ability make THEPC an attractive DNA probe in TPM.展开更多
Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl)porphin (Pd-TAPP), in the presence of calf thymus DNA. Thes...Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl)porphin (Pd-TAPP), in the presence of calf thymus DNA. These results may be attributed to the site competition of MMC with the probe and electron transfer between MMC and probe. MMC also increases polarization degree of the probe by covalent drug-DNA or DNA-drug-DNA crosslinking.展开更多
DNA fingerprinting, developed in 1985, has now become a powerful tool forindividual identification and paternity testing in forensic casework and medicine. It hasalso found wide application to population genetics, evo...DNA fingerprinting, developed in 1985, has now become a powerful tool forindividual identification and paternity testing in forensic casework and medicine. It hasalso found wide application to population genetics, evolution, systematics and geneticlinkage analysis in animals, plants and even microorganisms. Conventional DNAfingerprinting requires specific multilocus minisatellite probes-or microsatellite展开更多
The microarray of DNA probes with 5′-NH2 and 5′-Tex/3′-NH2 modified terminus on 10 μm carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) is characterized in...The microarray of DNA probes with 5′-NH2 and 5′-Tex/3′-NH2 modified terminus on 10 μm carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) is characterized in the present paper. It was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentration of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.展开更多
Technique of recombinant DNA has been used for prenatal diagnosis of many kinds of genetic disorders and was also applied to the determination of fetal sex. In China, prenatal diagnosis of α-and β-thalassemia was do...Technique of recombinant DNA has been used for prenatal diagnosis of many kinds of genetic disorders and was also applied to the determination of fetal sex. In China, prenatal diagnosis of α-and β-thalassemia was done by this technique, but sex determination of fetus is still performed, by using chromosome analysis. The展开更多
The Plasmodtum falctparum DNA fragment was isolated from a cloned recombinant plasmid pPF14. labelled with Digoxigenin (Dig) and used as a probe (pPF14-F-Dig)to detect 274 blood samples from the eqdemic area populatio...The Plasmodtum falctparum DNA fragment was isolated from a cloned recombinant plasmid pPF14. labelled with Digoxigenin (Dig) and used as a probe (pPF14-F-Dig)to detect 274 blood samples from the eqdemic area population in Hainan Province by dot hybridization.The results showed that out of 274 blood specimens one was positive when using microscopic examination and the positivity rate was 0.36 percent. Fifteen samples showed to be positive (including one positive specimen examined by microscopy) when this probe was applied to detect the 274 samples and its positivity rate was 5.47 percent.The positive coincidence rate between pPF14-F-Dig and microscopic examination was 1/1 and the negative coincidence rate was 94.87 percent. Since a piece of nitrocellulose membrane with the size of 9 by 12 square centimetres can accommodate blots of 96 samples,this probe is fit for large-scale epidemiological surveys.展开更多
文摘In this study,the DNA probe pPF14 was nonradioactively labelled by sulfo-modifica-tion,and used in a dot blot hybridization assay for detection of P.falciparum.The resultsshowed that the sulfoprobe successfully detected 25pg purified DNA and 0.001% parasitemia ofcultured P.falciparum,and did not react with human leukocyte DNA.In the study of 179clinical blood samples of malaria patients from Yunnan province,the DNA probe results corre-lated well with blood smear ones.Of 107 P.falciparum samples determined by microscope ex-amination,99 were positive by sulfoprobe (92.5%);Of 72 P.vivax samples,1 was crosslyreacted;no cross reactions were found with any of 48 normal blood samples.It is indicated thatsulfoprobe may be useful in specific diagnosis and epidemiological investigation of P.falciparuminfection.
基金Supported by Fund of Guangdong Provincial Administration of Traditional Chinese Medicine(20111251)
文摘To screen species-specific DNA probes for identification of Fallopia muhiflora, the genomic DNA (gDNA) suppression subtraction hybridization (SSH) between F. muhiflora and F. muhiflora var. ciliinervis was firstly performed. The obtained differential gDNA fragments by SSH were then hybridized with gDNA ar- rays consisting of multiple whole genomes of several species (adulterants and/or closely related species of F. muhiflora) and four differential fragments were screened uniquely representing F. muhiflora, which could be used as F. muhiflora species-specific probes. The screened DNA probes were tested by reverse dot blot hybridization and the results demonstrated that these probes could be used reliably to identify F, muhiflora. The species-specific DNA probes obtained in this study exhibited broad application prospects in the preparation of gene chips for identifying Chinese traditional medicines and the authentication of germplasm re- sources and crude drugs of F. muhiflora.
文摘A commercially available non—radioactive DNA labelling kit "enhanced chemiluminescence"(ECL) was evaluated for the diagnosis of falciparum malaria. The results showed that ECL labeled probe successfully detected as little as 25 pg. Purified DNA of 0.001% parasitemia of cultured Plasmodium falciparum and did not react with human
文摘Subject Code:B05 With the support by the National Natural Science Foundation of China and the US National Institutes of Health,a team led by Dr.Tan Weihong(谭蔚泓)at Hunan University and the University of Florida reported a new DNA probe for studying cell membrane interactions,which was recently published
文摘AIM: To develop a real-time PCR for detecting hepatitis B virus-(HBV) DNA based on TaqMan technology using a new MGB probe.METHODS: Plasmid containing the sequence of X gene (1414-1744 nt) was constructed as HBV-DNA standard for quantitative analysis. A TaqMan-MGB probe between primers for amplification was designed to detect PCR products. The interested sequence contained in the plasmid and in clinical specimens was quantitatively measured.RESULTS: The detection limit of the assay for HBV DNA was 1 genome equivalent per reaction. A linear standard curve was obtained between 100 and 109 DNA copies/reaction (r>0.990). None of the negative control samples showed false-positive reactions in duplicate. HBV DNA was detected in 100% (50/50) of HBV patients with HbeAg, and in 72.0% (36/50) with HBsAg, HBeAb and HBcAb. The coefficient of variation for both intra- and inter-experimental variability demonstrated high reproducibility and accuracy.CONCLUSION: Real-time PCR based on TaqMan-MGB probe technology is an excellent method for detection of HBV DNA.
基金financially supported by the National Natural Science Foundation of China (51603171 and 51373131)Talent Project of Southwest University (SWU115034)+2 种基金Fundamental Research Funds for the Central Universities (XDJK2016C032)Key Laboratory of Polymeric Composite & Functional Materials of Ministry of Education (PCFM201605)Hubei Key Laboratory of Advanced Textile Materials & Application (Fzxcl2017003)
文摘Sterically spacing and locating functional matters at the nanoscale exert critical effects on their application,especially for the fluorescence probes whose aggregation causes emission quenching.Here we achieved a hierarchical spacing strategy of DNA fluorescence probes for ion detection via locating them separately on rod-like cellulose nanocrystals(CNCs)and further isolating CNCs by pre-grafting long molecular chains.Controlling chemical structure of CNC and location degree could adjust the interspace of DNA probes(with a molecular length of ca.3.6 nm)in a range of 3.5-6.5 nm with a gradient about 0.2 nm.A length up to micrometer scale of the CNC nanorods was necessary to provide DNA probes with well-separated grafting locations and enough freedom,which brought a vast linear detection range from 10 nmol/L to 5 μmol/L of Hg^2+ concentration.The abundant reactive sites on CNC allowed a grafting pre-location of poly(tert-butyl acrylate)(PtBA)to promote the isolation of DNA probes.Controlled radical polymerization was employed to adj ust the length of PtBA molecular chains,which increased the linear sensitivity coefficient of Hg^2+ detection by ca.2.5 times.This hierarchical nanoscale spacing concept based on chemical design can hopefully cond uce to the development of biosensor and medical diagnosis.A hierarchical spacing strategy was applied to separate DNA fluorescent probes on CNCs and detect ion concentration linearly.The first-level spacing was to locate probes uniformly on CNCs,obtaining a wide linear range;and the second-level spacing was to isolate CNCs with polymer,obtaining an increased linear coefficient.
基金supported by the National Natural Science Foundation of China (50673053, 50173015, 30771091 and 50721002)National Science Foundation of China/the Hong Kong Research Grants Council (50218001)
文摘A new carbazole tricationic salt,4,4'-(1E,1'E)-2,2'-(9-(2-(1-(2-hydroxyethyl)pyridinium-4-yl)ethyl)-9H-carbazole-3,6-diyl) bis(ethane-2,1-diyl) bis(1-(2-hydroxyethyl)pyridinium) iodide (THEPC) was synthesized. Photophysical experiments have shown that THEPC has large two-photon excited fluorescence action cross-sections (33 GM in the presence of DNA),which ranks THEPC as a good biological fluorophore. The results from electronic absorption,circle dichroism and single-/two-photon fluorescence emission spectra suggest that THEPC can strongly bind to DNA,with an intrinsic binding constant of 5.79 × 106 L mol-1. THEPC has better photostability under one-or two-photon excitation conditions. Finally,the staining photos from two-photon fluorescence microscopy (TPM) show that THEPC can exclusively label the nucleus with high contrast and without image distortion. These remarkable properties and optimized imaging ability make THEPC an attractive DNA probe in TPM.
基金the National Natural Science Foundation of China (No. 29875016) Natural Science Foundation of Shanxi Province (No.991010) and the Ministry of State Education Foundation.
文摘Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl)porphin (Pd-TAPP), in the presence of calf thymus DNA. These results may be attributed to the site competition of MMC with the probe and electron transfer between MMC and probe. MMC also increases polarization degree of the probe by covalent drug-DNA or DNA-drug-DNA crosslinking.
文摘DNA fingerprinting, developed in 1985, has now become a powerful tool forindividual identification and paternity testing in forensic casework and medicine. It hasalso found wide application to population genetics, evolution, systematics and geneticlinkage analysis in animals, plants and even microorganisms. Conventional DNAfingerprinting requires specific multilocus minisatellite probes-or microsatellite
文摘The microarray of DNA probes with 5′-NH2 and 5′-Tex/3′-NH2 modified terminus on 10 μm carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) is characterized in the present paper. It was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentration of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.
文摘Technique of recombinant DNA has been used for prenatal diagnosis of many kinds of genetic disorders and was also applied to the determination of fetal sex. In China, prenatal diagnosis of α-and β-thalassemia was done by this technique, but sex determination of fetus is still performed, by using chromosome analysis. The
文摘The Plasmodtum falctparum DNA fragment was isolated from a cloned recombinant plasmid pPF14. labelled with Digoxigenin (Dig) and used as a probe (pPF14-F-Dig)to detect 274 blood samples from the eqdemic area population in Hainan Province by dot hybridization.The results showed that out of 274 blood specimens one was positive when using microscopic examination and the positivity rate was 0.36 percent. Fifteen samples showed to be positive (including one positive specimen examined by microscopy) when this probe was applied to detect the 274 samples and its positivity rate was 5.47 percent.The positive coincidence rate between pPF14-F-Dig and microscopic examination was 1/1 and the negative coincidence rate was 94.87 percent. Since a piece of nitrocellulose membrane with the size of 9 by 12 square centimetres can accommodate blots of 96 samples,this probe is fit for large-scale epidemiological surveys.