Total Viable Organism
Encyclopedia
Total viable organism is a term used in microbiology
to quantify the amount of microbial organisms present in a sample. Each sample is usually cultured
on a variety of agar plate
s (petri dish
es) often containing different types of selective media. The colony-forming unit
s (CFU
s) are calculated after allowing time for growth. TVO numbers are used to quantify the CFU
s for a given amount of sample and often include dilution factors.
For example, a 1 mL sample of water containing 10 CFU
s on one plate would have a TVO value of 10 cfu/mL
Microbiology
Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell , cell clusters or no cell at all . This includes eukaryotes, such as fungi and protists, and prokaryotes...
to quantify the amount of microbial organisms present in a sample. Each sample is usually cultured
Microbiological culture
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
on a variety of agar plate
Agar plate
An agar plate is a Petri dish that contains a growth medium used to culture microorganisms or small plants like the moss Physcomitrella patens.Selective growth compounds may also be added to the media, such as antibiotics....
s (petri dish
Petri dish
A Petri dish is a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells or small moss plants. It was named after German bacteriologist Julius Richard Petri, who invented it when working as an assistant to Robert Koch...
es) often containing different types of selective media. The colony-forming unit
Colony-forming unit
In microbiology, colony-forming unit is a measure of viable bacterial or fungal numbers. Unlike direct microscopic counts where all cells, dead and living, are counted, CFU measures viable cells...
s (CFU
CFU
CFU may refer to:* Cambridge Fans United, fans of the English football team Cambridge United F.C.* Canadian Freelance Union, a Canadian trade union for freelance media contributors* Caribbean Football Union, the nominal governing body for Caribbean football...
s) are calculated after allowing time for growth. TVO numbers are used to quantify the CFU
CFU
CFU may refer to:* Cambridge Fans United, fans of the English football team Cambridge United F.C.* Canadian Freelance Union, a Canadian trade union for freelance media contributors* Caribbean Football Union, the nominal governing body for Caribbean football...
s for a given amount of sample and often include dilution factors.
For example, a 1 mL sample of water containing 10 CFU
CFU
CFU may refer to:* Cambridge Fans United, fans of the English football team Cambridge United F.C.* Canadian Freelance Union, a Canadian trade union for freelance media contributors* Caribbean Football Union, the nominal governing body for Caribbean football...
s on one plate would have a TVO value of 10 cfu/mL