Online Microbiology and Biology Study Notes
What is positive staining? Positive staining of viruses is similar to negative staining. The difference is that the virus image is darker formed on a light background, unlike the negative staining where a light viral particle image is formed on a dark background. The technique is simple and it is used widely to study the diverse morphologies of viruses from …
What is the Negative staining of Viruses? Staining techniques are designed to show contrast under microscopic observation. The staining of viruses is done to increase the contrast between the virus and the background. The use of an electron microscope intensifies the density of electron toward the stain. Negative staining is one of the most excellent techniques in studying viruses, bacterial …
Viruses are intracellular pathogens that reproduce only in the living cell and manipulate the cellular machinery to produce more viruses. Viral replications can affect the cellular genes of the host in multiple cancerous ways. An oncovirus is a virus that can cause cancer. Viruses account for about 20% of total human cancer cases. Although many viruses can cause various tumors in animals, only seven of …
Viruses gain access to the host through skin and mucous membranes, and via the respiratory, gastrointestinal, and genital tracts. Their virulence or lack of it may be determined by very small mutations in the genome. Viral infection of cells may result in lysis, fusion and syncytium formation, the appearance of inclusion bodies, or, in some instances, transformation to cells with …