phosphorus-radioisotopes and photobiotin

Poly(ADP-ribose) is routinely detected by the use of radioactive polymers formed from labeled substrates. In this report a simple and time-saving method for the biotinylation and the detection of poly(ADP-ribose) on blots is described. The polymer modified by light-induced reaction with photobiotin was colorimetrically detected and quantified, using streptavidine-alkaline phosphatase conjugates. The separation of poly(ADP-ribose) chains on polyacrylamide gels was not affected by the biotinylation of the polymers. When biotinylated poly(ADP-ribose) was used to detect the poly(ADP-ribose) binding capability of proteins in ligand blots, the results were comparable to those obtained with poly([32P]ADP-ribose). Experiments with histones and rat liver nuclear proteins demonstrate that in studies on poly(ADP-ribose)-protein interaction, this method is applicable to the detection of poly(ADP-ribose) binding proteins.

Topics: Affinity Labels; Alkaline Phosphatase; Animals; Autoradiography; Azides; Bacterial Proteins; Biotin; Cell Nucleus; Colorimetry; Electrophoresis, Polyacrylamide Gel; Indicators and Reagents; Kinetics; Ligands; Light; NAD; Phosphorus Radioisotopes; Poly Adenosine Diphosphate Ribose; Proteins; Streptavidin

Photobiotin- and 32P-labelled DNA probes of L. interrogans sv. lai strain 017 were produced and the DNA and leptospires were dotted on the NC filter and hybridized. The results showed that photobiotin and 32P-labelled DNA probes could detect DNAs of homology. The smallest amount of DNA that could be detected with the probes were 5pg and 1pg, and the smallest numbers of pathogenic leptospires were 5 x 10(3) and 10(3), respectively. Nonpathogenic leptospires. L. biflexa sv. patoc strain Patoc 1, L. illini strain 3055, Escherichia coli, Bacillus aerogenes capsulatus, and Salmonella anatis, could not be detected by the probes. The study demonstrates that leptospires DNA probe could be produced by labelling the DNA with photobiotin. It has higher sensitivity and specificity and can be used for detection of leptospires in the field and clinic.

Topics: Affinity Labels; Azides; Biotin; DNA Probes; DNA, Bacterial; Immunoblotting; Leptospira interrogans; Nucleic Acid Hybridization; Phosphorus Radioisotopes

A dot-blot hybridisation assay for the detection of Campylobacter pylori was used to compare a 32P-labelled probe with two biotinylated probes and a sulphonated probe. The minimum amount of pure C. pylori DNA that could be detected by the 32P-labelled probe was 100 pg, which corresponded to 5 x 10(4) bacteria. A biotin-labelled DNA (biotin-DNA) probe together with the BluGeneTM detection system produced by Bethesda Research Laboratories (BRL), and a sulphonated probe and ChemiprobeTM detection system (Orgenics) gave similar levels of sensitivity; nylon membranes could be used with both these non-radioactive detection systems. However, a photobiotin-labelled DNA (photobiotin-DNA) probe and detection system produced by Biotechnology Research Enterprises S.A. (BRESA) gave optimum results only with nitrocellulose membranes, and was quantitatively 100 times less sensitive than the other types of probe. The detection systems for the biotin-DNA and photobiotin-DNA probes produced non-specific reactions with crude bacterial blots of heterologous organisms; these non-specific reactions could be removed by treating the dot blots with proteinase K, but not by treatment with RNAase. The sulphonated probe and detection system did not give any reaction with heterologous organism blots.

Topics: Azides; Biotin; Campylobacter; DNA, Bacterial; Membranes, Artificial; Nucleic Acid Hybridization; Nylons; Phosphorus Radioisotopes; Reagent Kits, Diagnostic; Sulfonic Acids