A known volume of sample can be spread onto the surface of an agar plate, or mixed with agar and poured onto a plate. Serially diluted samples enable obtaining a countable number of colonies on the agar surface. These two methods are supported by a technique called serial dilution. They are spread plate method and pour plate method.
There are two common methods used to measure CFU in a sample. The viable colonies that appear on the agar plates are expressed as CFU per 1 ml (colony forming unit per milliliter) of the sample for liquids or CFU per 1 g (colony forming unit per one gram) of the sample for solids. The method which counts colony forming units is referred as standard plate count. Side by Side Comparison – CFU vs MPN in Tabular FormĬolony forming unit (CFU) is a parameter which measures the number of viable bacterial or fungal cells in a given sample.
The key difference between CFU and MPN is that CFU is calculated from the bacterial and fungal colonies growing on a solid agar plate while MPN is calculated from viable bacteria growing in a liquid medium. Most probable number is another unit used to measure the number of viable bacterial cells in a liquid sample. The standard unit for this parameter is CFU/ml or CFU/g. Colony forming unit is a measure used to enumerate the number of viable bacterial cells or fungal cells in specific volume or weight of a given sample. Both parameters are used to detect water quality and fecal indicator bacteria in water samples. Colony forming unit (CFU) and Most probable number (MPN) are two methods used to enumerate microorganisms in samples.
0 kommentar(er)
