Tobacco mosaic virus (TMV) is a simple rod-shaped helical virus that contains single stranded RNA situated at its middle and is surrounded by a protein coat called capsid. After tobacco mosaic virus enters its infected host cells through mechanical inoculation, it removes its capsid to release its single stranded viral nucleic acid which is then transported into the nucleolus. The single stranded viral RNA actuates the production of specific enzymes (RNA polymerases) and it also produces another RNA strand (replicative RNA). The new viral-RNAs are transported from the nucleus into the cytoplasm and functions as messenger-RNAs (mRNAs). Each mRNA, ribosomes, and t-RNA, of the infected host cell all controls the production of protein subunits (capsomeres). After the production of the preferred capsomeres, the new viral-RNAs arrange the capsomeres around it which lead to the production of a complete virus particle (virion). The viruses then migrate from one cell to another. Hence, creating organized infection.
The volume you plate in the viable count method affect the final calculation of cells/ml. Counting the number of colonies that arise on a pour plate can help to calculate the final concentration by multiplying the count by the volume spread on the pour plate.
