Search results for "Agar gel"

Differences between cysteine and homocysteine in the induction of deoxyribose degradation and DNA damage.

2001

The effect of two naturally occurring thiols, such as cysteine and homocysteine, has been examined for their ability to induce deoxyribose degradation and DNA damage. Copper(II) ions have been added to incubation mixtures and oxygen consumption measurements have been performed in order to correlate the observed damaging effects with the rate of metal catalyzed thiol oxidation. Ascorbic acid plus copper has been used as a positive control of deoxyribose and DNA oxidation due to reactive oxygen species. Cysteine or homocysteine in the presence of copper ions induce the degradation of deoxyribose and the yield of 8-hydroxy-2'-deoxyguanosine (8-OHdG), although important differences are observed…

Survival in extreme dryness and DNA-single-strand breaks.

1992

A wide variety of organisms (the so-called "anhydrobiotes') is able to survive long periods of time in a state of utmost dehydration and can thus survive in extremely dry environments including artificially imposed or space vacuum. Known strategies of survival include the accumulation of certain polyols, especially disaccharides, which help prevent damage to membranes and proteins. Here we report that DNA in vacuum-dried spores is damaged to a very substantial degree by processes leading to DNA strand breaks. Most of these lesions are obviously repaired during germination, but extensive damage to DNA and enzymes after long exposure times (months to years) finally diminish the chances of sur…

Characterization of the carbapenem-hydrolyzing oxacillinase OXA-58 in an Acinetobacter phenon 6/ct13TU clinical isolate

2008

The bla(OXA-58) gene identified in the Acinetobacter phenon 6/ct13TU clinical isolate presented 100% homology with the same gene in Acinetobacter baumannii. Its location in a plasmid suggests that these resistance genes may be transferred from 1 species to another.

DNA Amplification Fingerprinting for Subtyping Neisseria gonorrhoeae Strains

1995

Background and Objectives DNA amplification fingerprinting is used in most epidemiologic studies as a substitute for conventional typing methods. DNA amplification fingerprinting and conventional typing methods were compared in this epidemiologic study of Neisseria gonorrhoeae. Goal of This Study To differentiate 70 Neisseria gonorrhoeae isolates from untreated patients with urogenital gonococcal infection. Study Design Gonococcal strains were characterized by auxo-typing, serotyping, plasmid profile, antibiotic sensitivity, and DNA amplification fingerprinting. The method of unweighted pair-group average linkage was used for cluster analysis. Discriminatory power was calculated applying Si…

R plasmids in environmental Vibrio cholerae non-O1 strains.

1988

The occurrence of drug resistance and its plasmid-mediated transferability was investigated in 140 environmental strains of Vibrio cholerae non-O1 and 6 strains of Vibrio cholerae, both O1 and non-O1, of clinical origin. Of the 146 strains tested, 93% were resistant to at least one drug and 74% were resistant to two or more antibiotics. The O1 strains were susceptible to all antibiotics used. A total of 26 of 28 selected resistant wild strains carried R plasmids that were transferable by intraspecific and intergeneric matings. The most common transmissible R factor determined resistance to ampicillin, amoxicillin, and sulfanilamide (30%), followed by resistance to ampicillin and amoxicillin…

Rapid DNA elution procedure from agarose gels.

1996

Increasing voltage gradient electrophoresis of DNA

2007

We developed a method which allows electrophoretic fractionation of DNA in an agarose matrix according to an increasing current gradient, using a previously designed [R. Barbieri, V. Izzo, M.A. Costa, G. Giudice, G. Duro, Anal. Biochem. 212 (1993) 168; M.R. Asaro, V. Izzo, R. Barbieri, J. Chromatogr. A 855 (1999) 723] voltage gradient apparatus. This method allows the separation of different DNA fragments by increasing the distances of the components fractionated in the gel, revealing small differences in the length of different DNA components.

A method for eluting DNA in a wide range of molecular weights from agarose gels

1991

We have developed a simple and rapid method for recovering DNAs of a wide range of molecular weights from agarose gels. A DNA-containing gel slice is placed on a Parafilm sheet in the center of a circular (positive) electrode and covered with a drop of buffer, while a linear (negative) electrode is placed on the top of the gel and driven about 1 mm into the gel itself. When a continuous current is applied, the DNA migrates into the buffer toward the circular electrode. We have obtained almost total recovery of DNAs up to 10 kb in size. Our method may also be used, under appropriate conditions, for higher molecular weight DNAs. The yield and all the biological assays performed on the DNAs ob…

Molecular monitoring of inactivation efficiencies of bacteria during pulsed electric field treatment of clinical wastewater

2008

Aims:  The applicability of an alternative wastewater disinfection concept based on the pulsed electric field (PEF) treatment is tested with molecular biology techniques using clinical wastewaters. Methods and Results:  Hospital wastewater was treated with the PEF technology. The inactivation efficiencies of bacteria were successfully monitored with real-time polymerase chain reaction (PCR). As the differentiation between living and dead bacterial cells is important for the determination of the disinfection efficiency, propidium monoazide (PMA) was applied. PMA selectively penetrates cells with compromised membranes and intercalates into the DNA inhibiting a subsequent PCR amplification. Th…

Phylogenetic reconstruction of the yeast genus Kluyveromyces: restriction map analysis of the 5.8S rRNA gene and the two ribosomal internal transcrib…

1998

Summary We have constructed restriction site maps of the 5.8S rRNA gene and the two ITS regions in 60 strains of Kluyveromyces genus. We test the value of this region as a phylogenetic indicator, and its possible use as a fast and easy method to identify species of this genus. Despite some minor incongruences, our results are in good agreement with previous phylogenetic reconstructions based on the 18S rRNA gene sequencing (Cai et al., 1996; James et al., 1997). A highly significant monophyletic group was formed by K. lactis, K. marxianus, K. aestuarii, K. dobzhanskii and K. wickerhamii, which should be considered the true Kluyveromyces genus. The other species of the genus were grouped wit…