Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 91

With few exceptions, virus particles are too small to be observed directly by light microscopy. However, they can be seen readily in the electron microscope. If a sample contains only one type of virus, the particle count can be determined. A virus preparation is mixed with a known concentration of latex beads, and the numbers of virus particles and beads are then counted, allowing the concentration of the virus particles in the sample to be determined by comparison.