Macromolecular Weights Determined by Direct Particle Counting. I. The Weight of the Bushy Stunt Virus Particle

1949 ◽  
Vol 71 (12) ◽  
pp. 4052-4057 ◽  
Author(s):  
Robley C. Williams ◽  
Robert C. Backus
Keyword(s):  
Virus Particle ◽  
Particle Counting

Method of virus particle counting using millipore filtration

Virology ◽  
1970 ◽  
Vol 42 (2) ◽  
pp. 544-547 ◽  
Author(s):  
Dominique Barbieri ◽  
Etienne Delain ◽  
Philippe Lazar ◽  
Gilbert Hue ◽  
Georges Barski
Keyword(s):  
Virus Particle ◽  
Particle Counting ◽  
Millipore Filtration

Improved Virus Particle Counting by Direct Sedimentation onto EM Grids

1981 ◽  
Vol 39 ◽  
pp. 404-405 ◽  
Author(s):  
Mahlon F. Miller ◽  
Edward J. Rdzok
Keyword(s):  
Virus Particle ◽  
Thin Section ◽  
Vertical Position ◽  
Present Communication ◽  
Millipore Filter ◽  
Virus Particles ◽  
Negative Stain ◽  
Particle Counting ◽  
Rotor Core ◽  
Reliable Procedure

Investigators who have attempted to sediment virus particles directly onto EM grids have reported problems with: a) tearing of plastic support films covering grid openings, b) uneven distribution of virus due to depression of support films in grid openings during ultracentrifugation, c) failure of sedimented and stained particles to adhere to support films, and d) lack of uniformity of negative stain. The design of a new particle counting rotor and its use in preparing particulate specimens for counting by either the pseudoreplication or thin section methods was previously reported. In the present communication, a simple and reliable procedure is described in which this rotor is utilized to sediment virus particles directly onto grids for counting. The rotor (Fig. 1) operates in the Beckman AirfugeTM tabletop ultracentrifuge.In preparation for counting, 500 mesh copper grids are sandwiched between parlodion support films and 5 mm2 Millipore filter squares (Fig. 2) which conveniently holds grids in a vertical position at the base of sector cells in the rotor core (Fig. 1).

Spontaneous Production of Type C Virus Particles in a Culture Derived from Rat Embryo Cells

1972 ◽  
Vol 30 ◽  
pp. 288-289
Author(s):  
Elizabeth S. Priori ◽  
T. Shigematsu ◽  
B. Myers ◽  
L. Dmochowski
Keyword(s):  
Virus Particle ◽  
Mouse Embryo ◽  
Calf Serum ◽  
Embryo Cell ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Mouse Embryo Cell ◽  
Mature Virus Particle ◽  
Embryo Cells ◽  
Type C

Spontaneous release of type C virus particles in long-term cultures of mouse embryo cells as well as induction of similar particles in mouse embryo cell cultures with IUDR or BUDR have been reported. The presence of type C virus particles in cultures of normal rat embryos has not been reported.NB-1, a culture derived from embryos of a New Zealand Black (NB) rat (rats obtained from Mr. Samuel M. Poiley, N.C.I., Bethesda, Md.) and grown in McCoy's 5A medium supplemented with 20% fetal calf serum was passaged weekly. Extracellular virus particles similar to murine leukemia particles appeared in the 22nd subculture. General appearance of cells in passage 23 is shown in Fig. 1. Two budding figures and one immature type C virus particle may be seen in Fig. 2. The virus particles and budding were present in all further passages examined (currently passage 39). Various stages of budding are shown in Figs. 3a,b,c,d. Appearance of a mature virus particle is shown in Fig. 4.

Improvement of monitoring of tertiary filtration with particle counting

2006 ◽  
Vol 6 (1) ◽  
pp. 1-9
Author(s):  
V. Miska ◽  
J.H.J.M. van der Graaf ◽  
J. de Koning
Keyword(s):  
Particle Surface ◽  
Minor Effect ◽  
Particle Size Distributions ◽  
Particle Volume ◽  
Mass Distributions ◽  
Particle Counting ◽  
Total Particle ◽  
Particle Counts ◽  
A Minor ◽  
Sample Dilution

Nowadays filtration processes are still monitored with conventional analyses like turbidity measurements and, in case of flocculation–filtration, with phosphorus analyses. Turbidity measurements have the disadvantage that breakthrough of small flocs cannot be displayed, because of the blindness regarding changes in the mass distributions. Additional particle volume distributions calculated from particle size distributions (PSDs) would provide a better assessment of filtration performance. Lab-scale experiments have been executed on a flocculation–filtration column fed with effluent from WWTP Beverwijk in The Netherlands. Besides particle counting at various sampling points, the effect of sample dilution on the accuracy of PSD measurements has been reflected. It was found that the dilution has a minor effect on PSD of low turbidity samples such as process filtrate. The correlation between total particle counts, total particle volume (TPV) and total particle surface is not high but is at least better for diluted measurements of particles in the range 2–10 μm. Furthermore, possible relations between floc-bound phosphorus and TPV removal had been investigated. A good correlation coefficient is found for TPV removal versus floc-bound phosphorus removal for the experiments with polyaluminiumchloride and the experiments with single denitrifying and blank filtration.

Homogeneous Digital Biosensor for Circulating Tumor DNA by Enumerating Dual-color Quantum Dot Complex

The Analyst ◽  
2021 ◽  
Author(s):  
Xiaojun Liu ◽  
Zhangjian Wu ◽  
Xinyi Lin ◽  
Wei Bu ◽  
Lei Qin ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Single Particle ◽  
Triple Helix ◽  
Circulating Tumor Dna ◽  
Cancer Management ◽  
Counting Approach ◽  
Particle Counting ◽  
Dual Color ◽  
One Step ◽  
Tumor Dna

Monitoring ctDNA in blood is important to cancer management. Here, we develop a one-step single particle counting approach for directly quantifying ctDNA in plasma. Hairpin DNA containing a triple helix...

scholarly journals Lower temperature influences Cauliflower mosaic virus systemic infection

2021 ◽  
Author(s):  
Roberto Alers-Velazquez ◽  
Sushant Khandekar ◽  
Clare Muller ◽  
Jennifer Boldt ◽  
Scott Leisner
Keyword(s):  
Nucleic Acid ◽  
Actin Cytoskeleton ◽  
Mosaic Virus ◽  
Virus Particle ◽  
Systemic Infection ◽  
Cauliflower Mosaic Virus ◽  
Particle Release ◽  
Systemic Symptoms ◽  
Lower Temperature ◽  
Temperature Exposure

AbstractLower temperatures delayed development of systemic symptoms by Cauliflower mosaic virus (CaMV) in two different plant hosts. However, lower temperature exposure increased CaMV nucleic acid levels in leaves of systemically-infected turnips. Furthermore, lower temperature altered the formation of aggregates formed by the CaMV major inclusion body (IB) protein, P6. Finally, lower temperature altered the architecture of the actin cytoskeleton. These data may suggest that lower temperatures alter the actin cytoskeleton, facilitating the formation of larger IBs that hold on to their internal virions more strongly than small ones, impairing virus particle release and causing a delay in systemic infection.

Uncertainty in particle counting and sizing procedures

AIHAJ ◽  
1976 ◽  
Vol 37 (2) ◽  
pp. 103-108 ◽  
Author(s):  
DAVID LEITH ◽  
MELVIN W. FIRST
Keyword(s):  
Particle Counting

An Automated Particle Counting Immunoassay (PACIA) for Determination of Blocking Antibodies against Timothy Grass Pollen in Sera from Desensitized Allergies

Allergy ◽  
1983 ◽  
Vol 38 (3) ◽  
pp. 173-182 ◽  
Author(s):  
R. Djurup ◽  
C. G. M. Magnusson ◽  
U. Minuva ◽  
I. Søndergaard ◽  
O. østerballe ◽  
...  
Keyword(s):  
Grass Pollen ◽  
Timothy Grass ◽  
Particle Counting ◽  
Timothy Grass Pollen ◽  
Blocking Antibodies
Sign in / Sign up

Export Citation Format

Share Document