What does CFU stand for in microbiology?

The term CFU stands for Colony Forming Unit in microbiology. It is a crucial concept used to estimate the number of viable microorganisms in a sample. When scientists culture bacteria or fungi, they often do so on a solid medium. Each visible colony that forms can be traced back to a single viable parent cell, which is why each colony can be referred to as a colony forming unit.

Using CFU as a measurement allows researchers to quantify the number of live microorganisms, as not all cells that may be counted under a microscope are capable of growing into colonies. This concept is essential in studies involving dilution plating, where samples are diluted to a point that individual microorganisms can be isolated and counted distinctly. It is integral to various applications in microbiology, including environmental monitoring, clinical diagnostics, and food safety testing.

The other choices do not accurately reflect commonly used terms in microbiology. For example, Cellular Fragmentation Unit and Cytoplasmic Fusion Unit lack definitions that align with standard microbiological practices, while Cultured Fungi Unit does not encompass the broader range of microorganisms that CFU can refer to, as it applies to both bacteria and fungi. Thus, the understanding of CFU is fundamental for microbiologists in accurately determining microbial populations.