Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Digoxigenin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

Sensitive and quantitative detection of PCR-amplified HIV-1 DNA products by an enzyme linked immunoassay following solution hybridization with two differently labelled oligonucleotide probes.

We have developed and evaluated an ELISA-based detection method for PCR-amplified HIV-1 DNA. The assay uses two oligonucleotide probes which are end-labelled at the 5'-end with biotin or digoxigenin, respectively. Upon solution hybridization of these probes which react with the same strand of amplified DNA product, the formed hybrids are bound to avidin-coated wells of a microtitre plate and detected by horseradish peroxidase-labelled antibodies directed against digoxigen and 3, 3', 5, 5'-tetramethylbenzidine as substrate. Factors critical for a high signal-to-noise ratio were the use of serum as blocking agent, the amount of biotin-labelled and digoxigenin-labelled oligonucleotide probes present in a reaction and the inactivation of Taq DNA polymerase. The method has a detection limit of 1-3 pg of amplified DNA and is quantitative in a range extending from 1 pg to at least 200 pg. In the background of 1 microgram of total DNA, one single-stranded copy of HIV-1 DNA can be detected after 35 cycles of amplification. A comparison of the ELISA-based detection method with primer extension analysis, a method previously shown to reach a similar detection limit, demonstrated complete agreement of the results of 118 amplified DNAs. The method proved simple, requires only about 3 h, and could easily be adapted to the detection of other amplified target DNAs.

Base Sequence↗

In situ hybridization of atrial natriuretic peptide mRNA in the endothelial cells of human umbilical vessels.

The localization of mRNA encoding preproatrial natriuretic peptide (ANP) was investigated in cultured human umbilical vein endothelial cells (HUVEC) and tissue preparations of umbilical vein and artery. The techniques used were in situ hybridization and in situ hybridization combined with immunocytochemistry, using 32P-radiolabelled and non-radioactive digoxigenin labelled complementary RNA probes. Human ANP mRNAs are mainly localized in the endothelial cells of the umbilical vein and, to a lesser extent, in the endothelial cells of the umbilical artery. The autoradiographic labelling and the intensity of digoxigenin staining were significantly reduced by treatment with RNase before in situ hybridization. This study provides unequivocal evidence for the expression of the ANP gene in the endothelial cells of human umbilical vessels, confirming that these endothelial cells have the ability to synthesize this peptide. The functional significance of the presence of the ANP mRNA in the endothelial cells of human umbilical vessels is discussed.

Atrial Natriuretic Factor↗

Fine-structural localization of proenkephalin mRNAs in the hypothalamic magnocellular dorsal nucleus of the guinea pig: a comparison of radioisotopic and enzymatic in situ hybridization methods at the light- and electron-microscopic levels.

With the aim of localizing proenkephalin mRNAs in neurons of the hypothalamic magnocellular dorsal nucleus of the guinea pig, we compared the in situ hybridization signals obtained on Vibratome sections with a method employing either a biotinylated or a digoxigenin-labeled oligonucleotide detected by means of the alkaline phosphatase reaction. Since the hybridization approach using the biotinylated probe was more sensitive than the digoxigenin method, the ultrastructural localization of hybrids in neurons of the magnocellular dorsal nucleus was studied by the use of the former procedure, and was further compared with results of in situ hybridization using a 35S-labeled probe. Biotin was detected via an amplified avidin-biotin-peroxidase complex. Radioactive hybrids were localized over extended cytoplasmic compartments rich in rough endoplasmic reticulum and also in nuclear indentations. The method based on biotinylated probe proved to be sensitive and provided high-resolution labeling in well-preserved specimens. Proenkephalin mRNAs were clearly localized within circumscribed cytoplasmic compartments. The immunoprecipitates were mainly observed within the rough endoplasmic reticulum, especially at the periphery of the cell. The reticulum was dominated by elongated parallel cisternae. The labeling also appeared in a paranuclear position, mainly in nuclear indentations. The labeling was found on the outer surface of the endoplasmic lamellae. The remainder of the reticulum was unlabeled. Neuronal processes were free of labeling.

Alkaline Phosphatase↗

Comparative studies of the protein binding of digoxin and its metabolites.

The protein binding of Digoxin (D), Dihydrodigoxin (DH), Digoxigenin Bisdigitoxoside (DB) and Digoxigenin Monodigitoxoside (DM) was concentration independent and unaltered by the presence of high concentrations of the analogous compounds. The respective percentage of protein binding for D, DH, DB and DM were 22%, 22%, 23% and 27%.

Adult↗

Oestradiol, a new hapten for detecting nucleic acid sequences by FISH.

Oestradiol has been conjugated to allylamine-dUTP with an 11-atom spacer to allow enzymatic incorporation of the label into DNA sequences. In a comparative DNA and mRNA FISH study we have used DNA probes that were either labelled with digoxigenin, biotin or oestradiol. Results show that oestradiol-labelled probes can detect DNA and RNA sequences in FISH equally well as digoxigenin- and biotin-labelled probes. Further, no crossreactivity between the various hapten-specific antibodies and the three haptens were observed. Binding of the rabbit anti-oestradiol antibody to endogenous oestrogen in various tissues was not observed under the conditions tested. In view of the increasing demands for multi-colour DNA and mRNA FISH applications, oestradiol is a welcome addition to the collection of haptens employed in FISH.

Animals↗

Characterization of eastern oyster (Crassostrea virginica Gmelin) chromosomes by fluorescence in situ hybridization with bacteriophage P1 clones.

Chromosome identification is an essential step in genomic research, which so far has not been possible in oysters. We tested bacteriophage P1 clones for chromosomal identification in the eastern oyster Crassostrea virginica, using fluorescence in situ hybridization (FISH). P1 clones were labeled with digoxigenin-11-dUTP using nick translation. Hybridization was detected with fluorescein-isothiocyanate-labeled anti-digoxigenin antibodies and amplified with 2 layers of antibodies. Nine of the 21 P1 clones tested produced clear and consistent FISH signals when Cot-1 DNA was used as a blocking agent against repetitive sequences. Karyotypic analysis and cohybridization positively assigned the 9 P1 clones to 7 chromosomes. The remaining 3 chromosomes can be separated by size and arm ratio. Five of the 9 P1 clones were sequenced at both ends, providing sequence-tagged sites that can be used to integrate linkage and cytogenetic maps. One sequence is part of the bone morphogenetic protein type 1b receptor, a member of the transforming growth factor superfamily, and mapped to the telomeric region of the long arm of chromosome 2. This study shows that large-insert clones such as P1 are useful as chromosome-specific FISH probes and for gene mapping in oysters.

Animals↗

Structural characterization of glycoprotein carbohydrate chains by using diagoxigenin-labeled lectins on blots.

The carbohydrate structures of blotted glycoproteins can be analyzed by probing them with lectins. Here we describe a method where lectins conjugated with digoxigenin are used in combination with an anti-digoxigenin antibody AP conjugate as a very sensitive detection system for this type of analysis. The specificity of the lectins used, and the sensitivity of the detection system, provide valuable conclusions on the glycan structures. Only small amounts of glycoproteins are required for the analysis. The binding specificity of a set of lectins is demonstrated with various glycoproteins of defined carbohydrate structure. The application of these labeled lectins in combination with specific glycosidases for the characterization of the carbohydrate chains of recombinant tissue plasminogen activator and erythropoietin is presented.

Animals↗

A nonradioactive screening method for cloning genes encoding sequence-specific DNA binding proteins.

We have developed a novel nonradioactive screening method for cloning genes encoding sequence-specific DNA binding proteins. This method is derived from previously described protocols developed for the same purpose by using radioactively labeled DNA probes containing protein recognition sequences. This nonradioactive strategy relies upon the use of a small hapten, digoxigenin. Fusion proteins expressed from the recombinant bacteriophage lambda gt11/lambda ZAP are immobilized on nitrocellulose filters and probed with digoxigenin-labeled double-stranded DNA as a ligand. The specifically bound DNA probes can be detected through sequential incubations with antibody-enzyme conjugate and enzyme substrates. This technique has been successfully utilized to isolate several cDNA clones encoding DNA binding proteins.

Bacteriophage lambda↗

Effects of K+ on the interaction between cardiac glycosides and Na,K-ATPase.

Inhibition of Na,K-ATPase by cardiac glycosides is at least partially antagonized by K+. The kinetics of the antagonism, however, appear complicated because K+ is capable of reducing both association and dissociation rate constants for the glycoside-enzyme interaction. In order to better understand the effect of K+, inhibition of partially purified Na,K-ATPase obtained from rat brain, guinea-pig heart and rat heart by ouabain, digoxin, digoxigenin, dihydrodigoxin and cassaine were compared in the presence of 1, 3 or 10 mM K+. Higher concentrations of K+ caused a parallel shift to the right in the concentration-inhibition curves for these compounds. For ouabain or digoxin, the extent of the shift was minimal with rat brain enzyme, intermediate with guinea-pig heart enzyme and more substantial with rat heart enzyme. For digoxigenin, dihydrodigoxin or cassaine, the extent of the shift was substantial in all enzyme preparations. These results could not be explained from either the affinity of the enzyme for the compound or its lipid solubility alone. The concentrations of these compounds required to cause a 50 percent inhibition of enzyme activity were markedly different with rat brain enzyme, but relatively similar with rat heart enzyme. The effects of K+, which depend on the source of the enzyme and chemical structures of the compounds, have to be considered in studies on comparative effects of various compounds on Na,K-ATPase, [3H]ouabain binding, sodium pumping and the force of myocardial contraction.

Abietanes↗

3'-end fluorochromized and haptenized oligonucleotides as in situ hybridization probes for multiple, simultaneous RNA detection.

We have used fluorescein-, digoxigenin- and biotin-(di)deoxyXTPs and terminal deoxynucleotidyl transferase for small scale labeling of synthetic oligonucleotide probes and here we show the applicability of such probes for the in situ detection of multiple RNA sequences. The enzymatic 3'-end-labeling methods proved to be good alternatives for the chemical fluorochrome and hapten labeling of 5'-end alkylamino-derivatized oligonucleotides. By combining 3'-end fluorescein-, biotin-, and digoxigenin-labeled oligonucleotides, double and triple hybridizations are feasible. For example, we demonstrated simultaneously mRNAs coding for caudodorsal cell hormone, a molluscan insulin-related peptide, and 28 S ribosomal RNA in cryostat sections of the cerebral ganglia of the pond snail Lymnaea stagnalis.

Animals↗

Evaluation of non-radioactive labelling and detection of deoxyribonucleic acids. Part One: Chemiluminescent methods.

The growth of analytical methods for the detection of nucleic acid from various biological samples reflects recent advances in biotechnology development especially in the areas of genetic, infections and cancer diagnosis. The target DNA is detected by hybridization techniques derived from Southern's blotting. However such assays, based on the use of 32P labelled DNA probes, bring with them the associated problems of handling radioactive materials. In order to overcome these difficulties, a number of chemiluminescent detection methods have recently been developed. These new, alternative probe labelling procedures and chemiluminescent detection methods are easy to use in routine assays performed in research laboratories as well as for medical applications, and can reach the level of sensitivity found in classical radiolabelling techniques. The techniques investigated include peroxydase, biotin 16-dUTP or digoxigenin 11-dUTP probe labelling. The target DNAs are transferred onto nitrocellulose or nylon membranes and further fixed by heat or UV crosslinking. Specific hybridization on the target DNA is finally revealed by the use of chemiluminescent substrates. For all these techniques the detection limit is 10 aM (attomol) of a 561 bp target DNA. However for the probes labelled with peroxydase and with digoxigenin the detection limit drops to 1.0 aM of the target DNA. In the present paper we shall compare several of these DNA labelling and detection procedures and show that the detection threshold can vary by as much as a factor of 20 from method to method. This is the first time that various chemiluminescent methods for label and detection of DNA are compared and evaluated in order to determine the best protocol.

Adamantane↗

Evaluation of non-radioactive labelling and detection of deoxyribonucleic acids. Part Two: Colorigenic methods and comparison with chemiluminescent methods.

The diagnosis of genetic infections and cancerous diseases is carried out more and more often at a molecular level using Southern's technique which is based on the use of 32P-labelled DNA. In order to circumvent the risks and rapid decrease in radioactivity associated with these latter techniques, new colorigenic methods have been developed. In this work, we describe the use of dTTP analogues (digoxigenin-dUTP and biotin-dUTP) for the labelling of probes and detection of target DNA. Using digoxigenin-11-dUTP, 0.1 aM of a 561 bp target DNA was detected by using a modified Southern procedure. The reliability and the high sensitivity of such methods make them a good tool for DNA investigation in research as well as in testing laboratories.

Adenocarcinoma↗

A nonradioactive riboprobe assay for the detection of hepatitis B virus DNA in human sera.

Sequences of hepatitis B virus DNA were detected specifically in the sera of infected individuals by a non-radioactive riboprobe nucleic acid hybridization assay. The nucleic acids contained in serum specimens were prepared by an overnight proteinase K-/SDS-digest, phenol/chloroform-extraction and ethanol-precipitation, and immobilized on nylon membranes by the dot-blot technique. Digoxigenin-labelled 1.4 kb RNA-probes were generated by the phage sp 6 RNA-polymerase from a linearized HBV DNA transcription template containing the appropriate promoter. Hybridized probes were detected by alkaline phosphatase-conjugated sheep anti-digoxigenin Fab-fragments, and 5-bromo-4-chloro-3-indolylphosphate (BCIP) and nitroblue tetrazolium salt (NBT) as chromogenic substrates for the subsequent ELISA procedure. With a detection limit of 0.5-1.0 pg HBV DNA and a high specificity, the results were comparable to those obtained by the standard assay employing radioactively labeled DNA-probes.

DNA Probes↗

Comparison of four non-radioactive and 35S-based methods for the detection of human papillomavirus DNA by in situ hybridization.

Human papillomavirus DNA was detected in 40 condylomatous lesions of various sites (vulva, cervix, larynx, penis and anus) by in situ hybridization using 35S-labelled probes and four non-radioactive probes to compare the various sensitivities of these techniques on the same material (formalin-fixed and paraffin-embedded sections). Radioactive probes yielded 28 positive results out of 40 (70%). Sulphonated probes (HybriCyte kit) also gave 28 positive results with a fine pattern of hybridization grains and equal sensitivity to 35S-labelled probes. Biotinylated and digoxigenin-labelled probes gave analogous results (25 positive reactions with the PathoGene kit, 26 with the Viratype kit, and 25 with digoxigenin-labelled probes) but are slightly less sensitive than radiolabelled and sulphonated probes especially when the signal is weak.

Adolescent↗

Colorimetric detection for PCR amplified HIV-1 DNA using magnetic beads.

A rapid and nonradioactive detection method for polymerase chain reaction (PCR) amplified HIV-1 DNA was developed using a colorimetric detection system. Hybridization between biotin-labeled amplified targets and digoxigenin-capture probes occurs in solution followed by efficient and rapid capture onto streptavidin-magnetic beads. The presence of the digoxigenin-capture probe hybridized with biotin-labeled targets is then detected by antidigoxigenin-alkaline phosphatase conjugates using a colorimetric substrate. This approach is highly sensitive and can detect less than 10 HIV targets prior to PCR in approximately 50 min.

Bacterial Proteins↗

Evaluation of three new techniques for the detection of STb-positive Escherichia coli strains.

A study was conducted to compare different techniques for the detection of heat-stable enterotoxin b (STb)-positive E. coli strains. Antisera against purified STb was used to develop an enzyme-linked immunosorbent assay (ELISA). STb-positive strains identified by ELISA were tested for bioactivity in rat jejunal loops. Our ELISA was as sensitive as, but less specific than, the bioassay for detection of STb-positive strains. A non-radioactive DNA probe to detect the gene coding for STb was also developed by incorporating digoxigenin-11-dUTP into DNA by the random primed labelling technique. The non-radioactive digoxigenin-labelled DNA probe demonstrated a similar detectability to the radioactive probe and was more convenient to manipulate but was less sensitive and specific than the bioassay and the radioactive probe. In addition, the polymerase chain reaction (PCR) was used to amplify a specific portion of the gene coding for STb. The PCR was a highly specific and practical technique for the detection of STb-positive strains. All E. coli strains tested containing the STb gene produced the STb toxin.

Bacterial Toxins↗

In situ PCR for in vivo detection of foreign genes transferred into rat brain.

Here we describe the use of in situ PCR to detect a viral transgene in rat brain. Previously, we have reported in vivo gene transfer by using a defective herpes simplex viral vector in mammalian brain (Kaplitt, M.G., Pfaus, J.G., Kleopoulos, S.P., Hanlon, B.A., Rabkin, S.D., Pfaff, D.W., Mol. Cell. Neurosci. 2 (1991) 320-330). For detection of the LacZ transgene, we have used histochemical staining for the protein product, beta-galactosidase, and in situ hybridization for its mRNA, but the DNA itself cannot be reliably detected with conventional methods. Therefore we have adapted the technique of in situ PCR, so that we may detect minute quantities of transgenic vector DNA following in vivo gene. The brain sections, prefixed, were treated with PBS-detergent before PCR amplification to increase permeability for peptides and oligonucleotides across cellular barriers in brain tissue. Pretreatment with detergent retained better brain morphology than the more widely used proteinase treatment. The PCR mixture containing dNTPs, primers, digoxigenin-dUTP (Dig-dUTP) and buffer was loaded onto each brain section. Slides containing brain sections were placed in an aluminum boat and then on the block of the thermal cycler. Temperature was brought to 82 degrees C before adding Taq polymerase ('hot start' method). Dig-labeled PCR amplified fragments were then detected by alkaline-phosphatase-linked anti-digoxigenin-antibody. Positive signals were seen within the nucleus of transduced neurons, indicating presence of viral DNA. Enhanced specificity was observed with the use of Dig-labeled primers which eliminates the possibility of non-specific viral DNA detection through primer-independent reactions. Overall, this technique can serve not only as an internal control for transgene presence during comparisons of experimental groups of animals, but may also have clinical applications including the detection of viral infection in human brain such as HIV in pathology specimens.

Animals↗

Quantitation of RT-PCR amplified cytokine mRNA by aequorin-based bioluminescence immunoassay.

We described here a bioluminescence-based immunoassay for the quantitation of RT-PCR amplified cytokine mRNA. This technique uses a standard RT-PCR procedure, with the following modifications. The forward primer in the PCR reaction is labeled with a 5' biotin molecule. Following PCR, a digoxigenin-conjugated oligonucleotide probe is hybridized to the target biotin-labeled DNA template. The hybridized duplex is captured onto a streptavidin-coated microtiter plate. The bound product is quantitated by adding digoxigenin-specific antibodies conjugated with the photoprotein aequorin. The amount of specific DNA captured onto the plate is quantitated by triggering the bioluminescence reaction through the addition of calcium ions. This technique detected as low as 40 amol of amplified cytokine products, or 500 copies of templates when 27 PCR cycles were used. The high sensitivity of this technique enables the quantitation of target DNA during the exponential phase of the PCR reaction. The aequorin-bioluminescence assay is an alterative non-radioactive method for the quantitation of PCR products.

Aequorin↗