The present paper is aimed to detect superparamagnetic iron oxide labeled c-erbB2 oncogene antisense oligonucleotide probe (magnetic antisense probe) connected with SK-Br-3 oncocyte mRNA nucleotide by high resolution atomic force microscope (AFM). We transfected SK-Br-3 oncocyte with magnetic antisense probe, then observed the cells by AFM with high resolution and detected protein expression and magnetic resonance imagine (MRI). The high resolution AFM clearly showed the connection of the oligonucleotide remote end of magnetic antisense probe with the mRNA nucleotide of oncocyte. The expression of e-erbB2 protein in SK-Br3 cells were highly inhibited by using magnetic antisense probe. We then obtained the lowest signal to noise ratio (SNR) of SK-Br-3 oncocyte transfected with magnetic antisense probe by MRI (P<0.05). These experiments demonstrated that the high resolution AFM could be used to show the binding of magnetic antisense probe and SK-Br-3 mRNA of tumor cell nuclear.
Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; DNA, Antisense ; chemistry ; genetics ; Female ; Ferric Compounds ; chemistry ; Genes, erbB-2 ; genetics ; Humans ; Magnetics ; Microscopy, Atomic Force ; methods ; Molecular Probe Techniques ; Nucleic Acid Probes ; chemistry ; genetics ; Oligodeoxyribonucleotides ; chemistry ; genetics ; Oxyphil Cells ; ultrastructure ; RNA, Messenger ; genetics ; metabolism

OBJECTIVETo develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray.

METHODSTwo 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 (Mon810, 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).

RESULTSA combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS1/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.

CONCLUSIONA combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.

Base Sequence ; Cloning, Molecular ; Crops, Agricultural ; DNA Primers ; DNA Probes ; Oligonucleotide Array Sequence Analysis ; Plants, Genetically Modified ; Polymerase Chain Reaction ; methods

OBJECTIVETo genotype single nucleotide polymorphisms (SNPs) in a large number of samples by applying three-dimensional polyacrylamide gel-based microarray.

METHODSThe method relies on copolymerization of acrylamide-modified PCR products with acrylamide monomers and acryl-modified slides to prepare gel-based microarray. Then array is hybridized with a pair of specific probes and the two universal dual-color fluorescent detectors labeled with Cy3 or Cy5 respectively (Tag1 and Tag2). Electrophoresis is used in post-hybridization to remove the nonspecifically bound targets and mismatches. Finally, genotyping is based on the images captured through two-color fluorescent scanning.

RESULTSThe 3-D gel-immobilization of nucleic acids has a high immobilization yield and good hybridization efficiency. As universal dual-color fluorescent detectors are used, it is not required that specific probes be labeled for all SNPs, therefore the expense for synthesis can be reduced considerably. Electrophoresis in post-hybridization can enhance the capability for discriminating a single nucleotide mismatch from the perfectly matched sequence and improve the signal-to-noise ratio significantly.

CONCLUSIONThe gel-based microarray is a rapid, simple and high-throughput method for SNPs genotyping and may be very competitive in the efficiency, fidelity and cost for constructing DNA microarrays, which will hold significant promise for applications in human DNA diagnostics.

DNA Mutational Analysis ; methods ; DNA Probes ; Electrophoresis, Polyacrylamide Gel ; methods ; Fluorescent Dyes ; Genotype ; Humans ; Molecular Diagnostic Techniques ; Nucleic Acid Hybridization ; methods ; Oligonucleotide Array Sequence Analysis ; methods ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide

OBJECTIVETo study the expression pattern of cd99l2 gene during zebrafish development, the RNA probes for whole-mount in situ hybridization were prepared in this study.

METHODSThe cd99l2 fragment obtained by RT-PCR was cloned into pGM-T Easy, then the plasmids were linearized with the restriction enzymes SacII or SalI. Using Sp6 or T(7) RNA polymerase, the digoxingenin-labeled antisense and sense probes were synthesized and confirmed by whole-mount in situ hybridization.

RESULTSThe plasmid cd99l2/pGM-T was constructed. cd99l2 gene expression pattern during embryogenesis of zebrafish was examined using the antisense probe, and intense expression was detected in the central nervous system during zebrafish development.

CONCLUSIONThe antisense probe can be used for study of the spatial and temporal distribution of cd99l2 during zebrafish development using the sense probe as control.

Animals ; Central Nervous System ; embryology ; Cloning, Molecular ; Digoxigenin ; chemistry ; Gene Expression Regulation, Developmental ; Oligonucleotide Probes ; RNA Probes ; Uridine Triphosphate ; chemistry ; Zebrafish ; embryology ; genetics ; Zebrafish Proteins ; genetics

OBJECTIVETo develop a simple and reliable method for intensifying the hybridization signals of gene chips.

METHODSThe authors added EDTA and another FAM-labeled probe to the normal PCR products, denatured the mixture by heat, and then let the mixture hybridize with the fastened probes on the chip.

RESULTSWith the use of EDTA and another FAM-labeled probe, the hybridization signals increased by 6 times or greater.

CONCLUSIONAdding EDTA and another probe to the normal PCR products is a simple and efficient method to intensify the hybridization signal of chips.

Base Sequence ; DNA Probes ; chemistry ; genetics ; Edetic Acid ; chemistry ; Fluorescent Dyes ; chemistry ; Microscopy, Fluorescence ; Molecular Sequence Data ; Nucleic Acid Hybridization ; methods ; Polymerase Chain Reaction ; methods ; Reproducibility of Results

OBJECTIVETo develop a TaqMan real-time PCR for the detection of Aeromonas hydrophila.

METHODSThe conserved region of major adhesion gene of Aeromonas hydrophila (aha) was used to design primers and TaqMan probe. A total of six concentration gradients for forward and reverse primers ranging from 200 -700 nmol/L were chosen, and four concentration gradients for probe ranging from 100 - 400 nmol/L were chosen. And then the concentration of primers and probe were optimized by ANOVA of completely randomized design respectively. The specificity of the established method was evaluated by using bacteria as contrast, including 45 strains Vibrio cholerae, 20 strains Vibrio parahaemolyticus, 10 strains Vibrio fluvialis, 4 strains Vibrio mimicus, 5 strains Vibrio vulnificus, 1 strain Vibrio alginolyticus, 1 strain Vibrio furnissii, 5 strains Salmonella, 10 strains Shigella and 2 strains Plesiomonas shigelloides. The sensitivity, bacterial sensitivity and DNA sensitivity included,were evaluated. The stool of healthy people was contaminated by Aeromonas hydrophila artificially, and the ability of the established TaqMan real-time PCR system for detection of Aeromonas hydrophila was also evaluated.

RESULTSThe cycle threshold (Ct) value deserved from 6 groups of primers concentration gradient was (x +/- s):20.69 +/- 0.33, 20.72 +/- 0.21, 20.81 +/- 0.12, 20.74 +/- 0.12, 20.51 +/- 0.16 and 20.69 +/- 0.11, respectively, and the concentration of forward primer and reverse primer was determined to be 200 nmol/L (F = 1.33, P = 0.28). The Ct value deserved from 4 groups of probe concentration gradient was (x +/- s):20.56 +/- 0.08, 20.82 +/- 0.05, 20.82 +/- 0.11 and 20.93 +/- 0.09, respectively, and the concentration of probe was determined to be 100 nmol/L (F = 5.26, P = 0.01). The bacterial sensitivity and DNA sensitivity were 80 CFU/ml and 100 fg/microl respectively, and the sensitivity to detect Aeromonas hydrophila from stool was 8 x 10(3) CFU/ml, which might be 8 CFU/ml after 8 hours' enrichment. No amplification was observed in the templates of other bacterial.

CONCLUSIONThe TaqMan real-time PCR method targeting the aha gene of Aeromonas hydrophila had a high sensitivity and specificity and might be used to detect Aeromonas hydrophila from pure bacterial and stool rapidly.

Aeromonas hydrophila ; genetics ; DNA Primers ; Genes, Bacterial ; Molecular Probes ; Polymerase Chain Reaction ; methods ; Sensitivity and Specificity ; Species Specificity

OBJECTIVETo develop a real-time polymerase chain reaction(PCR) based on TaqMan technology by using a new MGB probe for detecting enterotoxigenic Escherichia coli (ETEC) in paper.

METHODSPrimers and MGB probe were designed in the ecoding region of heat-stable toxin of ETEC. Real-time PCR detected ETEC by using the exterior standard method with protracting standard curves. The specificity, sensitivity, accuracy, stability of real-time PCR system was evaluated. An internal negative antithesis was added to the real-time PCR system in order to get rid of the false positive of system. Using UNG enzyme expelled the contamination of PCR reaction.

RESULTSPrimers and MGB probe were suited to the Real-time PCR. The assay showed that the method was quick, special, sensitive and stable. The real-time PCR system could detect ETEC in a large scale. The assay might be finished in two hour.

CONCLUSIONThese observations suggested that real-time PCR based on MGB probe should be an excellent candidate for a standard ETEC detection method.

Bacterial Toxins ; isolation & purification ; DNA Primers ; DNA Probes ; DNA, Bacterial ; Enterotoxigenic Escherichia coli ; isolation & purification ; Molecular Probe Techniques ; Polymerase Chain Reaction ; methods ; Taq Polymerase

OBJECTIVETo develop a new platform for genotyping human papillomavirus (HPV) and to investigate its effect in clinical application.

METHODSA pair of common primers of 18 HPV subtypes for PCR, was designed in HPV conservative L1 region. Genotyping probes for detecting 15 high-risk HPV subtypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68, together with 3 low-risk HPV 6, 11 and 42 were selected respectively from Genbank and fixed on membrane to make DNA chip. PCR amplification and DNA chip technology were optimized. 100 clinical samples were used to investigate the effect of HPV genotyping DNA chip. Veracity of the genotyping results was verified by sequencing.

RESULTSFrom the 100 clinical samples, 30 were found to be HPV positive, including high-risk HPV subtypes 16, 18, 33, 45, 51, 58, and 66, and low-risk HPV 6, 11 and 42. The sensitivity tested by standard samples was up to 10 copies of HPV DNA.

CONCLUSIONThe HPV genotyping system developed here with DNA chip showed high sensitivity and specificity, suitable to be applied in clinical practice for HPV diagnosis and investigation on the prevalence of HPV sub-types.

DNA Probes, HPV ; genetics ; DNA, Viral ; genetics ; Female ; Genotype ; Humans ; Molecular Sequence Data ; Oligonucleotide Array Sequence Analysis ; methods ; Papillomaviridae ; classification ; genetics ; isolation & purification ; Papillomavirus Infections ; diagnosis ; virology ; Polymerase Chain Reaction ; Sensitivity and Specificity ; Uterine Cervical Neoplasms ; virology

The aim of this study was to develop and validate an oligonucleotide suspension array for rapid identification of 15 bacterial species responsible for bacteremia, particularly prevalent in Chinese hospitals. The multiplexed array, based on the QIAGEN LiquiChip Workstation, included 15 oligonucleotide probes which were covalently bound to different bead sets. PCR amplicons of a variable region of the bacterial 23S rRNA genes were hybridized to the bead-bound probes. Thirty-eight strains belonging to 15 species were correctly identified on the basis of their corresponding species-specific hybridization profiles. The results show that the suspension array, in a single assay, can differentiate isolates over a wide range of strains and species, and suggest the potential utility of suspension array system to clinical laboratory diagnosis.
Bacteremia ; diagnosis ; genetics ; Bacterial Typing Techniques ; Bacteriological Techniques ; DNA Probes ; Genetic Techniques ; Listeria monocytogenes ; metabolism ; Nucleic Acid Hybridization ; Oligonucleotide Array Sequence Analysis ; Oligonucleotides ; chemistry ; RNA, Ribosomal ; chemistry ; RNA, Ribosomal, 23S ; genetics ; Stem Cells

Two oligonucleotide probes are permitted to anneal to the nucleic acid target of interest so that the ends of two probes immediately become adjacent to each other. The ligase can then efficiently join the two juxtaposed oligonucleotide probes by the formation of a phosphodiester bond if and only if perfectly matched base-pairs at the nick are present. During past 20 years, many ligase-mediated techniques have been developed for analyzing various bio-molecules, such as known/unknown point mutations, small-scale insertions and deletions, CpG islands methylation, large sets of single nucleotide polymorphisms (SNPs), specific proteins and DNA regions with which some other proteins can interact. Since the ligation reaction can be easily integrated into other techniques, certain advances have been already achieved. These novel approaches retain high accuracy through multiple hybridization and enzymatic processing events, and provide inherent quality control checking. In this article, we provide a comprehensive review of the ligase-mediated techniques for bio-molecular analysis.
CpG Islands ; genetics ; DNA Methylation ; Ligases ; metabolism ; Molecular Probe Techniques ; Mutation ; Oligonucleotide Probes ; biosynthesis ; chemical synthesis ; genetics ; Polymorphism, Single Nucleotide