In-Gel Isolation and Characterization of Large (and Other) Phages

We review some aspects of the rapid isolation of, screening for and characterization of jumbo phages, i.e., phages that have dsDNA genomes longer than 200 Kb. The first aspect is that, as plaque-supporting gels become more concentrated, jumbo phage plaques become smaller. Dilute agarose gels are better than conventional agar gels for supporting plaques of both jumbo phages and, prospectively, the even larger (>520 Kb genome), not-yet-isolated mega-phages. Second, dilute agarose gels stimulate propagation of at least some jumbo phages. Third, in-plaque techniques exist for screening for both phage aggregation and high-in-magnitude, negative average electrical surface charge density. The latter is possibly correlated with high phage persistence in blood. Fourth, electron microscopy of a thin section of a phage plaque reveals phage type, size and some phage life cycle information. Fifth, in-gel propagation is an effective preparative technique for at least some jumbo phages. Sixth, centrifugation through sucrose density gradients is a relatively non-destructive jumbo phage purification technique. These basics have ramifications in the development of procedures for (1) use of jumbo phages for phage therapy of infectious disease, (2) exploration of genomic diversity and evolution and (3) obtaining accurate metagenomic analyses.

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Isolation and Characterization of Fusarium moniliforme var. subglutinans from Malformed Mango

Journal of Agricultural and Marine Sciences [JAMS] ◽

10.24200/jams.vol4iss2pp19-25 ◽

1999 ◽

Vol 4 (2) ◽

pp. 19

Author(s):

K.P. Akhtar ◽

M. Asif ◽

M.A. Khan ◽

M.J. Jaskani ◽

I.A. Khan

Keyword(s):

Fusarium Moniliforme ◽

Culture Media ◽

Isolation And Characterization ◽

Ph Conditions ◽

Fungal Association ◽

Mango Malformation ◽

Growth Characters ◽

Better Than

Mango malformation occurs in most mango growing regions of the world. Floral and vegetative malformation have been reported. There is general agreement that the fungal pathogen Fusarium moniliforme var. subglutinans or Fusarium subglutinans is the causal agent. Healthy and malformed samples of both floral and vegetative tissues were collected from different varieties of mango grown in several locations to verify the association of F.moniliforme with mango malformation disease in Pakistan. The fungus was isolated and cultured. Frequency of fungal association with the disease ranged between 90- 94%, There was less recovery of fungus from asymptomatic tissue (12- 15%). There was no difference among the commercial mango varieties in the level of susceptibility to this disease. However, seedling germplasm and land races showing resistance to mango malformation were identified. The in vitro growth characters of the fungus were determined on different culture media, at varying temperatures, light and pH conditions. Mycelial growth on potato dextrose agar was better than nine other media tested. At pH 7.00, the ideal temperature for growth was between 25-30° C. Normally, the malformation is not controlled by fungicide application. The in vitro sensitivity of fungus to six fungicides at three concentrations was determined to seek potential means of chemical control.

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Isolation and characterization of enterohaemorrhagic Escherichia coli O157[ratio ]H7 from cattle in Belgium and Poland

Epidemiology and Infection ◽

10.1017/s0950268802007197 ◽

2002 ◽

Vol 129 (1) ◽

pp. 41-47 ◽

Cited By ~ 18

Author(s):

A. V. TUTENEL ◽

D. PIERARD ◽

J. URADZINSKI ◽

E. JOZWIK ◽

M. PASTUSZCZAK ◽

...

Keyword(s):

Phage Type ◽

Immunomagnetic Separation ◽

E Coli ◽

Slaughter Cattle ◽

Isolation And Characterization ◽

Enterohaemorrhagic Escherichia Coli ◽

Faecal Samples ◽

Peptone Water ◽

Ferment Lactose

EHEC O157 were isolated from faeces of Belgian and Polish beef slaughter cattle. In Belgium, 1281 faecal samples were analysed by immunomagnetic separation [IMS] after enrichment in buffered peptone water from June 1998 till July 1999. Eighty-one samples (6.3%) were positive for E. coli O157. Phage type 8 was most frequently found. Bulls between 1 and 2 years old, slaughtered in September and October were most frequently found positive. Atypical biochemical features were observed in some isolates: 22 (27%) isolates were urease positive and 1 (1.2%) isolate was unable to ferment lactose. In Poland, 551 faecal samples, taken from January 1999 till December 1999, were examined using exactly the same techniques. Four faecal samples (0.7%) were positive for O157 EHEC, yielding seven phage type 8 isolates. All positive samples were from cattle younger than 2 years. Positive samples occurred in August, September and October.

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Spectroscopic Ellipsometry as a Non-Destructive Technique for Characterization of Atomic-Scale Interfaces

MRS Proceedings ◽

10.1557/proc-159-459 ◽

1989 ◽

Vol 159 ◽

Author(s):

J.L. Stehle ◽

J.P. Piel ◽

J.H. Lecat ◽

C. Pickering ◽

L.C. Hammond

Keyword(s):

Spectroscopic Ellipsometry ◽

Crystalline Silicon ◽

Linear Regression Analysis ◽

Atomic Scale ◽

Physical Parameters ◽

Oxide Interfaces ◽

Non Destructive ◽

Calculated Model ◽

Better Than

ABSTRACTAnalysis of oxide interfaces with semi-conductor substrates, such as crystalline silicon, gallium arsenide, or indium phosphide is critical in processing and electrical performances. Interfaces can be characterized by spectroscopic ellipsometry (SE), which has a wide spectral range (1.3 to 5.3 eV ) allowing an optical penetration depth of 10 nm to a few microns.A multilayer stack can be characterized in terms of its layer thicknesses and composition. These physical parameters must be calculated through a mathematical model. Linear regression analysis is used to minimize the differences between the measured spectrum and the calculated model. If necessary, an interlayer can be introduced into the model to enhance the fit. This can be complemented by a new method involving calculation of apparent index values which amplifies interface sensivity allowing the thickness to be measured to better than 2 Angstroms. Examples will be given.

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Isolation and Characterization of Connexin26 Gap Junctions from Transfected Hela Cells

Microscopy and Microanalysis ◽

10.1017/s1431927600033729 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 246-247

Author(s):

G. Hand ◽

V. Nguyen ◽

K. Downing ◽

D. Mueller ◽

A. Engel ◽

...

Keyword(s):

Amino Acid ◽

Gap Junctions ◽

Hela Cells ◽

Multigene Family ◽

Similar Sequence ◽

Isolation And Characterization ◽

Extracellular Loops ◽

Junction Structure ◽

Better Than

Gap junctions are composed of a multigene family of proteins called the connexins with a similar sequence and folding topology. Connexons, half-channels made from a particular connexin, will dock and form functional channels with some, but not all, connexons made of other isoforms. This is surprising considering that the primary sequences of the docking domains are conserved and in some cases there are limited amino acid changes in the extracellular loops between compatible connexins. Therefore, some tertiary or quaternary interactions between the extracellular loops of the two docking hemichannels must contribute to the compatibility of a connexon assembled from one connexin for a connexon made from a different connexin. The 3D structures of gap junctions composed of only three isoforms have been investigated with only one case of a gap junction structure at better than 1 nm resolution [1]. The rat liver hemichannel structure is the only one that contains an exposed extracellular surface [2].

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Isolation and Characterization of a New Denitrifying Spirillum Capable of Anaerobic Degradation of Phenol

Applied and Environmental Microbiology ◽

10.1128/aem.66.4.1286-1291.2000 ◽

2000 ◽

Vol 66 (4) ◽

pp. 1286-1291 ◽

Cited By ~ 45

Author(s):

Yoshifumi Shinoda ◽

Yasuyoshi Sakai ◽

Makiko Ué ◽

Akira Hiraishi ◽

Nobuo Kato

Keyword(s):

Dna Sequences ◽

Enrichment Culture ◽

Aerobic Growth ◽

Ferrous Ions ◽

Degrading Bacterium ◽

Isolation And Characterization ◽

Degrading Bacteria ◽

Enrichment Process ◽

Better Than

ABSTRACT Two kinds of phenol-degrading denitrifying bacteria,Azoarcus sp. strain CC-11 and spiral bacterial strain CC-26, were isolated from the same enrichment culture after 1 and 3 years of incubation, respectively. Both strains required ferrous ions for growth, but strain CC-26 grew better than strain CC-11 grew under iron-limited conditions, which may have resulted in the observed change in the phenol-degrading bacteria during the enrichment process. Strain CC-26 grew on phenol, benzoate, and other aromatic compounds under denitrifying conditions. Phylogenetic analysis of 16S ribosomal DNA sequences revealed that this strain is most closely related to aMagnetospirillum sp., a member of the α subclass of the class Proteobacteria, and is the first strain of a denitrifying aromatic compound-degrading bacterium belonging to this group. Unlike previously described Magnetospirillumstrains, however, this strain did not exhibit magnetotaxis. It grew on phenol only under denitrifying conditions. Other substrates, such as acetate, supported aerobic growth, and the strain exhibited microaerophilic features.

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Scanning microwave microscopy of buried CMOS interconnect lines with nanometer resolution

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078718000181 ◽

2018 ◽

Vol 10 (5-6) ◽

pp. 556-561 ◽

Cited By ~ 3

Author(s):

Xin Jin ◽

Kuanchen Xiong ◽

Roderick Marstell ◽

Nicholas C. Strandwitz ◽

James C. M. Hwang ◽

...

Keyword(s):

Spatial Resolution ◽

Signal To Noise Ratio ◽

Signal To Noise ◽

Promising Technique ◽

Microwave Microscopy ◽

Interconnect Lines ◽

Scanning Microwave Microscopy ◽

Non Destructive ◽

Better Than

This paper reports scanning microwave microscopy of CMOS interconnect aluminum lines both bare and buried under oxide. In both cases, a spatial resolution of 190 ± 70 nm was achieved, which was comparable or better than what had been reported in the literature. With the lines immersed in water to simulate high-k dielectric, the signal-to-noise ratio degraded significantly, but the image remained as sharp as before, especially after averaging across a few adjacent scans. These results imply that scanning microwave microscopy can be a promising technique for non-destructive nano-characterization of both CMOS interconnects buried under oxide and live biological samples immersed in water.

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Characterization of Rh/Si multilayer structure by HREM and HAADF

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121016 ◽

1992 ◽

Vol 50 (1) ◽

pp. 122-123

Author(s):

Y. Cheng ◽

J. Liu ◽

M.B. Stearns ◽

D.G. Steams

Keyword(s):

Normal Incidence ◽

High Resolution Electron Microscopy ◽

X Rays ◽

Beam Direction ◽

Cross Sectional ◽

Optical Elements ◽

Resolution Electron ◽

Point To Point ◽

Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

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