Partial denaturation of mouse DNA in preparative cesium chloride density gradients at alkaline pH

Biochemistry ◽  
1976 ◽  
Vol 15 (9) ◽  
pp. 1865-1873 ◽  
Author(s):  
Thomas R. Cech ◽  
Gary Wiesehahn ◽  
John E. Hearst
Keyword(s):  
Cesium Chloride ◽  
Density Gradients ◽  
Alkaline Ph ◽  
Partial Denaturation

scholarly journals THE RELEASE AND STABILITY OF THE LARGE SUBUNIT OF DNA FROM T2 AND T4 BACTERIOPHAGE

1959 ◽  
Vol 42 (3) ◽  
pp. 503-523 ◽  
Author(s):  
Charles A. Thomas
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
Phage Particle ◽  
Large Subunit ◽  
Cesium Chloride ◽  
Density Gradients ◽  
Reaction Products ◽  
T4 Bacteriophage

T2 and T4 bacteriophage have been exposed to various treatments which are known to release the encapsulated DNA. The unseparated reaction products have been examined by autoradiography. The results indicate the presence of one large subunit of DNA (molecular weight 45 x 106) for each former phage particle. Some smaller subunits of molecular weight 12 x 106 have been observed. The large subunit is sensitive to very small amounts of DNAase, and is resistant to mixed proteases and cannot be dispersed by banding in cesium chloride density gradients. The sensitivity to fragmentation by P32 decay and the increase in this sensitivity following heat treatment are best explained by assuming that the large subunit is a duplex of polynucleotide strands over most of its length. The presence of hypothetical non-DNA interconnections is considered.

scholarly journals Standard Bacteriophage Purification Procedures Cause Loss in Numbers and Activity

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 328
Author(s):  
Amanda Carroll-Portillo ◽  
Cristina N. Coffman ◽  
Matthew G. Varga ◽  
Joe Alcock ◽  
Sudha B. Singh ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Cesium Chloride ◽  
Density Gradients ◽  
Purification Process ◽  
Mixed Sample ◽  
High Concentrations ◽  
Sample Measurement ◽  
Phage Population

For decades, bacteriophage purification has followed structured protocols focused on generating high concentrations of phage in manageable volumes. As research moves toward understanding complex phage populations, purification needs have shifted to maximize the amount of phage while maintaining diversity and activity. The effects of standard phage purification procedures such as polyethylene glycol (PEG) precipitation and cesium chloride (CsCl) density gradients on both diversity and activity of a phage population are not known. We have examined the effects of PEG precipitation and CsCl density gradients on a number of known phage (M13, T4, and ΦX 174) of varying structure and size, individually and as mixed sample. Measurement of phage numbers and activity throughout the purification process was performed. We demonstrate that these methods, used routinely to generate “pure” phage samples, are in fact detrimental to retention of phage number and activity; even more so in mixed phage samples. As such, minimal amounts of processing are recommended to introduce less bias and maintain more of a phage population.

scholarly journals Application of GelGreen™ in Cesium Chloride Density Gradients for DNA-Stable Isotope Probing Experiments

PLoS ONE ◽  
2017 ◽  
Vol 12 (1) ◽  
pp. e0169554 ◽  
Author(s):  
Jingfeng Gao ◽  
Kailing Pan ◽  
Hongyu Li ◽  
Xiaoyan Fan ◽  
Lixin Sun ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Cesium Chloride ◽  
Stable Isotope Probing ◽  
Density Gradients

Fractionation of Shope papilloma virus in cesium chloride density gradients

Virology ◽  
1962 ◽  
Vol 17 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Charles Breedis ◽  
Leonard Berwick ◽  
Thomas F. Anderson
Keyword(s):  
Cesium Chloride ◽  
Density Gradients ◽  
Papilloma Virus ◽  
Shope Papilloma Virus

Replication of Bacteriophage 186 DNA

1972 ◽  
Vol 30 ◽  
pp. 194-195
Author(s):  
Dhruba K. Chattoraj ◽  
Ross B. Inman
Keyword(s):  
Electron Microscopy ◽  
Dna Replication ◽  
Frame Of Reference ◽  
Dna Molecules ◽  
E Coli ◽  
Phage Dna ◽  
Partial Denaturation

Electron microscopy of replicating intermediates has been quite useful in understanding the mechanism of DNA replication in DNA molecules of bacteriophage, mitochondria and plasmids. The use of partial denaturation mapping has made the tool more powerful by providing a frame of reference by which the position of the replicating forks in bacteriophage DNA can be determined on the circular replicating molecules. This provided an easy means to find the origin and direction of replication in λ and P2 phage DNA molecules. DNA of temperate E. coli phage 186 was found to have an unique denaturation map and encouraged us to look into its mode of replication.

The Fine Structure of Replicating Simian Adenoviruses in LLC-MK2

1968 ◽  
Vol 26 ◽  
pp. 220-221
Author(s):  
Matias Pardo ◽  
Malcolm Slifkin ◽  
Leonard Merkow ◽  
Marie Sanchez
Keyword(s):  
Tissue Culture ◽  
Post Infection ◽  
Cesium Chloride ◽  
Longitudinal Section ◽  
Tubular Structures ◽  
Virus Particles ◽  
Ultrastructural Studies ◽  
Culture Cells ◽  
Simian Adenovirus ◽  
Infectivity Titer

The simian adenoviruses SV20, SV30 and SA7 have been found to be oncogenic in the Syrian hamster. The growth characteristics and replicative cycle of these viruses in tissue culture therefore appeared appropriate to investigate. Cesium chloride purified simian adenovirus with an infectivity titer of 100 TCID50, was inoculated into monolayers of LLC-MK2 cells. Cells were fixed in osmium tetroxide and embedded for ultrastructural studies at 1, 3, 6, 9, 18, 24, 48, 72, 120 and 192 hours post-infection.At the first hour post-infection, virus particles were adsorbed to the plasmalemma and found within the peripheral cytoplasm of many LLC-MK2 cells (Fig. 1). Although the first detection of infectious virus occurred at 14 hours and infectivity titers did not reach a maximum until 30 hours, intranuclear virus particles were observed by 3 hours in typical adenovirus crystalline array (Fig. 2) by means of electron microscopy. These typical honeycomb arrayed virus particles at 3 hours provided evidence of significant replication in approximately 5 percent of tissue culture cells examined. Simultaneously, a classical nuclear inclusion manifested by peripheral condensation of nuclear chromatin was evident by light microscopy. As early at 6 to 9 hours, unusual intranuclear concentric membranes formed “tubes” which contained linear arranged virus particles (Fig. 3). In transverse or tangential sections, these “tubes” appeared cochlear-like in shape. In longitudinal section, these intranuclear tubular structures contained individual virus particles at various stages of maturation in a linear arranged order. This arrangement resembled “peas in a pod”.

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