![]() ![]() Knowing how to determine the number of microorganisms in a sample is extremely important in microbiology, and requires accurate pipetting, aseptic technique, and calculation skills. Method for estimating the number of bacteriophages " Viruses have high specificity for its host, and will only infect a specific bacterium host. This type of bacteriophage is called a "coliphage. One common phage is called " T4" and it is capable of infecting its host, Escherichia coli. As the surrounding cells are infected and killed by the released viruses, a clear spot on the agar-in the bacterial lawn-develops, called a plaque.The plaques can be counted and the number of virus particles or virions in the original specimen, can be quantified as viruses/ ml or plaque-forming units/ml (PFUs). The bacteria have been poured into what is called a bacterial lawn on the agar plate. As the virus infects bacterial cells that it has been mixed with, the lytic infection destroys the bacteria. In fact, the ability to be infected with a known phage type is used to identify some strains of bacteria (like Staph), known as phage typing. Most bacteria have phages that are able to parasitize them. Viruses multiply within host cells and rely upon the host's metabolic machinery for replication. PHAGE (as in phagocytosis) means "to eat", and generally refers to a virus. ![]() Bacteriophages are viruses which infect bacteria. Viruses are obligate intracellular parasites that multiple within the host cytoplasm. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |