ABSTRACT
A significant dependence between different ionic strength and pH value of virus suspension on one hand and the haemagglutinin (HA) content as determined by single-radial-immunodiffusion (SRD) test on the other hand was observed after cleavage of influenza virus recombinant NIB-6 (H1N1) with sodium lauroyl sarcosinate (SLS). In contrast, no such relationship was found when the HA Of NIB-4 (H3N2) recombinant strain was determined.
Subject(s)
Hemagglutinins, Viral/analysis , Immunodiffusion , Influenza A virus/immunology , Hydrogen-Ion Concentration , Influenza A virus/genetics , Osmolar Concentration , Recombination, GeneticABSTRACT
The growth properties of pseudorabies virus (PRV) strain V BUK, wild type and its four ts mutants, were examined using highly accurate temperature measurements in the incubator and on the cell sheet. The transition from permissive to nonpermissive temperature occurred within an interval of 1 degree C. The midpoint of this interval was termed the semipermissive temperature since at this temperature the reproduction and consequently the plaquing of mutant viruses was not completely restricted. The "leakiness" of ts mutants might be due to their incubation at semipermissive temperature. Under semipermissive conditions and at high virus inputs, three mutants exhibited nearly complete inhibition of plaquing. In an experimental mixture of to mutants and PRV-BUK wild type, the latter was not affected by the inhibition. This might be due to an enhanced sensitivity of the mutants, but not of the wild type, to interferon under these conditions.
Subject(s)
Herpesvirus 1, Suid/growth & development , Hot Temperature , Mutation , Herpesvirus 1, Suid/genetics , Phenotype , Viral Plaque AssaySubject(s)
Influenza Vaccines/immunology , Animals , Antibodies, Viral/biosynthesis , Guinea Pigs , Hemagglutination Inhibition Tests , Hemagglutinins, Viral/analysis , Humans , Influenza A virus/genetics , Influenza A virus/immunology , Influenza A virus/pathogenicity , Influenza, Human/prevention & control , Methods , Mutation , Neuraminidase/analysis , Quality Control , Rabbits , Recombination, Genetic , Vaccines, Attenuated , VirulenceSubject(s)
Education, Medical , Berlin , Curriculum , Self-Evaluation Programs , Task Performance and Analysis , Teaching/methodsABSTRACT
Nine ts mutants of pseudorabies virus (PRV) strain BUK were isolated following bromodeoxyuridine (BUdR) or NaNO2 mutagenesis by a selection technique based on a shiftdown from nonpermissive to permissive temperature. This technique is described and its advantages are discussed. The nine ts mutants have been assigned to four complementation groups.
Subject(s)
Herpesviridae/genetics , Herpesvirus 1, Suid/genetics , Mutation , Animals , Bromodeoxyuridine , Chick Embryo , Culture Techniques , Genetic Complementation Test , Herpesvirus 1, Suid/growth & development , Herpesvirus 1, Suid/isolation & purification , Mutagens , Nitrites , Selection, Genetic , Temperature , Virus ReplicationABSTRACT
An economic method for quantitative assay of viruses is presented. In this "canule stick-plaque test" (German abbreviation SPT) samples of viruses, geometrically diluted and taken up by a canule, are inoculated by sticking into monolayer cell cultures overlayed with agar medium. A plaquelike CPE detectable by neutral red staining develops in the area of the inoculation. The frequency of this CPE formation depends on the concentration of viruses in the inoculated dilution. This dose-response allows calculation of the ID 50. In this way it is possible to carry out titration involving 6 dilutions and 10 inoculations per dilution using 3 common Petri dishes (6 cm in diameter), only. The sensitivity , accuracy, and reproductibility of this method are described and discussed.
Subject(s)
Viral Plaque Assay/methods , Viruses/isolation & purification , Animals , Chick Embryo , Culture Techniques , Cytopathogenic Effect, Viral , Herpesvirus 1, Suid/isolation & purification , Influenza A virus/isolation & purification , Sindbis Virus/isolation & purificationABSTRACT
An economic method for quantitative assay of viruses is presented. In this "canule stick-plaque test" (German abbreviation SPT) samples of viruses, geometrically diluted and taken up by a canule, are inoculated by sticking into monolayer cell cultures overlayed with agar medium. A plaquelike CPE detectable by neutral red staining develops in the area of the inoculation. The frequency of this CPE formation depends on the concentration of viruses in the inoculated dilution. This dose-response allows calculation of the ID50. In this way it is possible to carry out titration involving 6 dilutions and 10 inoculations per dilution using 3 common Petri dishes (6 cm in diameter), only. The sensitivity, accuracy, and reproductibility of this method are described and discussed.
