AIMTo explore a method to replace the isotope probe in the PCR-Select differential screening Kit with DIG labeled probe.

METHODSDifferential expressed sequences isolated from Suppression Subtractive Hybridization (SSH) was translocated onto nitric fibrin film. Probes were prepared with DIG-11-dUTP mixed in by PCR. Hybridization and coloration followed routine operation procedures of DIG labeled probe. Positive hybridization results were verified with reverse Northern blot.

RESULTSThe positive results from the PCR-Select differential screening Kit improved with DIG labeled probe achieved 90% correspondence verified by reverse Northern blot.

CONCLUSIONThe PCR-Select differential screening Kit improved with DIG labeled probe maintained high specificity while avoiding isotope pollution. It can replace isotope probe completely.

DNA Probes ; Digoxin ; Nucleic Acid Hybridization ; Polymerase Chain Reaction ; instrumentation ; methods ; Reagent Kits, Diagnostic

BACKGROUND: Exon deletions of Duchenne muscular dystrophy (DMD) gene account for most of the alterations found in DMD and Becker muscular dystrophy (BMD). This study was to evaluate the usefulness of dual priming oligonucleotide multiplex PCR (DPO PCR) in detection of exon deletions of DMD gene. METHODS: Thirty-seven DMD or BMD patients who had known exon deletions detected by conventional multiplex PCR (conventional PCR) and nine control subjects were enrolled in this study. When a discrepancy was shown between the results of conventional PCR and DPO PCR, the multiplex ligation-dependent probe amplification (MLPA) technique was performed as a confirmation test. RESULTS: The same deletions previously identified by conventional PCR in 32 out of 37 subjects were also detected by DPO PCR. For the five subjects (13.5%) showing discrepant results between the conventional PCR and DPO PCR, MLPA was performed and its results were found to correlate better with those of DPO PCR. The discrepancies were due to false positive or false negative results of the conventional PCR. CONCLUSIONS: DPO PCR shows a high agreement of results with the conventional PCR and is considered an adequate method to be used as a primary genetic test for the diagnosis of DMD. Because of an improved accuracy, especially for determining the boundaries of DMD gene deletions, DPO PCR can be very useful as a supplement to the conventional PCR.
*DNA Mutational Analysis ; DNA Primers ; Dystrophin/*genetics ; Female ; Gene Deletion ; Genetic Screening ; Humans ; Male ; Muscular Dystrophy, Duchenne/*diagnosis/genetics ; Nucleic Acid Amplification Techniques ; Oligonucleotide Probes ; Polymerase Chain Reaction/*methods ; Reagent Kits, Diagnostic ; Reproducibility of Results

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

BACKGROUND: Peptide nucleic acid (PNA) probes are artificial DNA analogues with a hydrophobic nature that can penetrate the mycobacterial cell wall. We evaluated a FISH method for simultaneous detection and identification of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM) in clinical respiratory specimens using differentially labeled PNA probes. METHODS: PNA probes targeting the mycobacterial 16S ribosomal RNA were synthesized. The cross-reactivity of MTB- and NTM-specific probes was examined with reference strains and 10 other frequently isolated bacterial species. A total of 140 sputum specimens were analyzed, comprising 100 MTB-positive specimens, 21 NTM-positive specimens, and 19 MTB/NTM-negative specimens; all of them were previously confirmed by PCR and culture. The PNA FISH test results were graded by using the United States Centers for Disease Control and Prevention-recommended scale and compared with the results from the fluorochrome acid-fast bacterial stain. RESULTS: The MTB- and NTM-specific PNA probes showed no cross-reactivity with other tested bacterial species. The test results demonstrated 82.9% agreement with the culture results with diagnostic sensitivity of 80.2% and diagnostic specificity of 100.0% (kappa=0.52, 95% confidence interval: 0.370-0.676). CONCLUSIONS: Dual-color PNA FISH showed high specificity for detecting and identifying mycobacteria in clinical specimens. However, because of its relatively low sensitivity, this method could be more applicable to culture confirmation. In application to direct specimens, the possibility of false-negative results needs to be considered.
Cell Wall ; Centers for Disease Control and Prevention (U.S.) ; DNA ; Fluorescence* ; In Situ Hybridization* ; Mycobacterium tuberculosis* ; Nucleic Acid Probes* ; Peptide Nucleic Acids ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; Sputum

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 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

Multiplex ligation-dependent probe amplification (MLPA) is a semiquantitative analysis based on polymerase chain reaction (PCR). It possesses many advantages such as high efficiency, simple operation, low cost and has been wildly applied in researches of diseases associated with copy number variation, point mutation and methylation. Recently, MLPA is combined with DNA chip to become a real high-throughput method and get great improvement in reliability. Here, the progresses of methods and application of MLPA, as well as its limitations are reviewed.
DNA Methylation ; DNA Probes ; analysis ; genetics ; Humans ; Nucleic Acid Amplification Techniques ; instrumentation ; methods ; Oligonucleotide Array Sequence Analysis ; Polymorphism, Single Nucleotide

In order to identify the differentially expressing gene of bone marrow mesenchymal stem cells (MSCs) stimulated by electromagnetic field (EMF) with osteogenesis microarray analysis, the bone marrow MSCs of SD rats were isolated and cultured in vitro. The third-passage cells were stimulated by EMFs and total RNA was extracted, purified and then used for the synthesis of cDNA and cRNA. The cRNA of stimulated group and the control group was hybridized with the rat oligo osteogenesis microarray respectively. The hybridization signals were acquired by using X-ray film after chemiluminescent detection and the data obtained were analyzed by employing the web-based completely integrated GEArray Expression Analysis Suite. RT-PCR was used to identify the target genes: Bmp1, Bmp7, Egf and Egfr. The results showed that 19 differentially expressing genes were found between the stimulated group and the control group. There were 6 up-regulated genes and 13 down-regulated genes in the stimulated group. Semi-quantitative RT-PCR confirmed that the expressions of Bmp1, Bmp7 mRNA of the stimulated group were up-regulated (P<0.05) and those of Egf, Egfr were down-regulated (P<0.05). It was suggested that the gene expression profiles of osteogenesis of the bone marrow MSCs were changed after EMF treatment. It is concluded that the genes are involved in skeletal development, bone mineral metabolism, cell growth and differentiation, cell adhesion etc.
Bone Marrow Cells/*cytology ; Cell Differentiation ; Down-Regulation ; Electromagnetic Fields ; Gene Expression Profiling ; Gene Expression Regulation ; Mesenchymal Stem Cells/*cytology ; Nucleic Acid Hybridization ; Oligonucleotide Probes/chemistry ; Osteogenesis/*genetics ; RNA, Complementary/metabolism ; Reverse Transcriptase Polymerase Chain Reaction

We report here a novel membrane transfer-based DNA detection method, in which alkaline phosphatase labeled gold nanoparticle (AuNP) probes were used as a means to amplify the detection signal. In this method, the capture probe P1, complimentary to the 3' end of target DNA, was immobilized on the chip. The multi-component AuNP probes were prepared by co-coating AuNPs with the detecting probe P2, complimentary to the 5' end of target DNA, and two biotin-labeled signal probes (T10 and T40) with different lengths. In the presence of target DNA, DNA hybridization led to the attachment of AuNPs on the chip surface where specific DNA sequences were located in a "sandwich" format. Alkaline phosphatase was then introduced to the surface via biotine-streptavidin interaction. By using BCIP/NBT alkaline phosphatase color development kit, a colorimetric DNA detection was achieved through membrane transfer. The signal on the membrane was then detected by the naked eye or an ordinary optical scanner. The method provided a detection of limit of 1 pmol/L for synthesized target DNA and 0.23 pmol/L for PCR products of Mycobacterium tuberculosis 16S rDNA when the ratio of probes used was 9:1:1 (T10:T40:P2). The method described here has many desirable advantages including high sensitivity, simple operation, and no need of sophisticated equipment. The method can be potentially used for reliable biosensings.
Colorimetry ; methods ; DNA Probes ; chemistry ; genetics ; DNA, Bacterial ; genetics ; Gold ; chemistry ; Humans ; Metal Nanoparticles ; chemistry ; Mycobacterium tuberculosis ; isolation & purification ; Nucleic Acid Hybridization ; methods ; Oligonucleotide Array Sequence Analysis ; methods

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