The Osmium Tetroxide Bipyridine-labeled DNA Probe: Hairpin Conformations and Characterization of Redox-label Behavior

2016 ◽  
Vol 29 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Hamdi Joda ◽  
Ada Sedova ◽  
Waqas Awan ◽  
Gerd-Uwe Flechsig
2003 ◽  
Vol 93 (5) ◽  
pp. 596-603 ◽  
Author(s):  
Jeri D. Barak ◽  
Robert L. Gilbertson

Bacterial leafspot of lettuce (BLS), caused by Xanthomonas campes-tris pv. vitians, has become more prevalent in many lettuce-growing areas of the world over the past decade. To gain insight into the nature of these outbreaks, the genetic variation in X. campestris pv. vitians strains from different geographical locations was examined. All strains were first tested for pathogenicity on lettuce plants, and then genetic diversity was assessed using (i) gas-chromatographic analysis of bacterial fatty acids, (ii) polymerase chain reaction analysis of repetitive DNA sequences (rep-PCR), (iii) DNA sequence analysis of the internal transcribed spacer region 1 (ITS1) of the ribosomal RNA, (iv) restriction fragment length polymorphism (RFLP) analysis of total genomic DNA with a repetitive DNA probe, and (v) detection and partial characterization of plasmid DNA. Fatty acid analysis identified all pathogenic strains as X. campestris, but did not consistently identify all the strains as X. campestris pv. vitians. The rep-PCR fingerprints and ITS1 sequences of all pathogenic X. campestris pv. vitians strains examined were identical, and distinct from those of the other X. campestris pathovars. Thus, these characteristics did not reveal genetic diversity among X. campestris pv. vitians strains, but did allow for differentiation of X. campestris pathovars. Genetic diversity among X. campestris pv. vitians strains was revealed by RFLP analysis with a repetitive DNA probe and by characterization of plasmid DNA. This diversity was greatest among strains from different geographical regions, although diversity among strains from the same location also was detected. The results of this study suggest that these X. campestris pv. vitians strains are not clonal, but comprise a relatively homogeneous group.


2010 ◽  
Vol 16 (4) ◽  
pp. 456-461 ◽  
Author(s):  
Valentina Bello ◽  
Giovanni Mattei ◽  
Paolo Mazzoldi ◽  
Nicoletta Vivenza ◽  
Paolo Gasco ◽  
...  

AbstractLipid-containing nanostructures, in the form of solid lipid nanoparticles or iron oxide nanoparticles (NPs) coated with a lipid shell, were used as case studies for assessing and optimizing staining for transmission electron microscopy structural and compositional characterization. These systems are of paramount importance as drug delivery systems or as bio-compatible contrast agents. In particular, we have treated the systems with a negative (phospshotungstic acid) or with a positive (osmium tetroxide) staining agent. For iron-oxide NPs coated with the lipid shell, negative staining was more efficient with respect to the positive one. Nevertheless, in particular cases the combination of the two staining procedures provided more complete morphological and compositional characterization of the particles.


1999 ◽  
Vol 172 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Carla Fontana ◽  
Marco Favaro ◽  
Domenico Frezza ◽  
Cartesio Favalli

Acta Tropica ◽  
1990 ◽  
Vol 48 (2) ◽  
pp. 109-116 ◽  
Author(s):  
M. Vogel ◽  
N. Müller ◽  
B. Gottstein ◽  
K. Flury ◽  
J. Eckert ◽  
...  

2012 ◽  
Vol 117 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Hyo-Sup Shin ◽  
Akimitsu Okamoto ◽  
Yasushi Sako ◽  
Sok Won Kim ◽  
Soo Yong Kim ◽  
...  

1998 ◽  
Vol 61 (5) ◽  
pp. 519-524 ◽  
Author(s):  
THOMAS P. OSCAR

A study was conducted with the RiboPrinter, an automated ribotyping system, to evaluate its ability to identify and characterize isolates of Salmonella from broiler operations. Isolates of Salmonella obtained from a local broiler company were serotyped by a reference laboratory and ribotyped using the RiboPrinter. The RiboPrinter generated ribotype patterns by probing EcoRI digests of Salmonella DNA with an E. coli DNA probe to the ribosomal RNA operon. The RiboPrinter identified isolates by band matching of their ribotype patterns to ribotype patterns in its database. In addition, the RiboPrinter characterized isolates by sorting them into ribotypes on the basis of the similarity of their ribotype patterns. Of 117 isolates, the RiboPrinter identified 34 (29%) at the serotype level, 11 (9%) at the strain level, 46 (39%) at the genus level, and 26 (22%) were not identified. Thus, only 38% of the isolates were identified at or below the serotype level, indicating that the RiboPrinter was limited in its ability to identify Salmonella isolates by band matching. In contrast, the RiboPrinter was very effective at characterizing Salmonella isolates. Out of 108 isolates, the RiboPrinter detected 31 ribotypes, compared to serotyping which only detected 22 types of Salmonella. Thus, automated ribotyping was more discriminatory than serotyping. However, when results of both typing methods were combined, 40 types of Salmonella were detected, indicating that the best discrimination was obtained when automated ribotyping and serotyping were used together.


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