To increase the contrast between viruses and the background, electron-dense "stains" are used.

Dr. Kidd conducted extensive research about the relationship between viruses and cancer.

However, there are several important differences between retroviruses and viruses from the Caulimoviridae family.

In addition, he investigated possible links between viruses and some forms of cancer.

It would be even more difficult to distinguish between viruses your body is accustomed to and those with which Hiroko infected you.

Scientists have noted other links between viruses and cancers.

An association between viruses and obesity has been found in humans as well as a number of different animal species.

An association between viruses and obesity has been found in humans and several different animal species.

In the past they were positioned somewhere between viruses and true bacteria.

Replication between viruses is greatly varied and depends on the type of genes involved in them.