Software to calculate CFU

Colonies can be enumerated from the picture of the plate using software tools.Experimenters typically take pictures of each plate they need to count and then analyze all the pictures (this can be done with a simple digital camera or even a webcam).Since it takes less than 10 seconds to take a picture instead of the minutes it would take to manually calculate the CFU, this approach often saves a lot of time. Also,it is more objective and allows extraction of other variables such as colony size and color.

1.OpenCFU[ is a free and open-source program optimized for user-friendliness,speed and robustness.It offers a wide range of filters and controls and a modern user interface.OpenCFU is written in C++ and uses OpenCV for image analysis.

2.NICE is a program written in MATLAB that provides an easy way to count colonies in an image.

3.ImageJ and CellProfiler:Some ImageJ macros and plugins and some CellProfiler pipelines can be used to count colonies.This often requires users to change code to achieve an efficient workflow,but can prove useful and flexible.A major problem is the lack of a specific GUI, which can make interacting with processing algorithms tedious.In addition to traditional desktop computer-based software,apps for Android and iOS devices are also available for semi automatic and automatic colony counting.Integrated camera to take pictures of agar plates and use internal or external algorithms to process image data and estimate colony counts. 

Automated system

Many automated systems are used to counteract human error,as many research techniques that count individual cells by humans are likely to make mistakes. Since researchers regularly count cells manually with the help of transmitted light, this error-prone technique can have a major impact on calculated concentrations in primarily liquid media when cell numbers are low.Some biotech manufacturers also offer fully automated systems.They are usually expensive and less flexible than stand-alone software because the hardware and software are designed to work together for a specific setting.Alternatively,some automated systems use a spiral plating paradigm.Some automated systems, such as those from MATLAB,can count cells without staining.This allows colonies to be reused for other experiments without the risk of killing microbes with useful stains.However,a disadvantage of these automated systems is that it is difficult to distinguish microorganisms from dust or scratches on blood agar plates,as both dust and scratches produce highly diverse combinations of shapes and appearances

Alternative unit

Parametric most probable numbers (MPN) and modified Fishman units (MFU) [citation needed] can be used instead of colony forming units.The most probable number method counts viable cells and is useful when counting low concentrations of cells or counting microorganisms in products where particles make plate counts impractical.The modified Fishman unit takes into account viable but nonculturable bacteria.