CFU stands for and what does it measure in bacterial culture?

CFU stands for and what does it measure in bacterial culture?

• A. Colony Forming Units; it measures the total cell count in the culture
• B. Colony Forming Units; it measures the number of colonies present
• C. Colony Forming Units; it measures viable cells capable of forming colonies
• D. Colony Fragmentation Units; it measures the rate of fragmentation

Answer: (C)

CFU stands for Colony Forming Units, and it measures the number of viable cells that are capable of growing into colonies on a solid growth medium. This means the count reflects living, reproducing cells, not all cells present in the sample. A single viable cell can give rise to a colony, so counting colonies after plating diluted samples (and expressing the result as CFU per mL) estimates how many living cells were in the original culture. It does not measure dead cells or total cell count, and it isn’t just about the number of colonies alone without accounting for dilution. It also isn’t about fragmentation.

CFU stands for Colony Forming Units, and it measures the number of viable cells that are capable of growing into colonies on a solid growth medium. This means the count reflects living, reproducing cells, not all cells present in the sample. A single viable cell can give rise to a colony, so counting colonies after plating diluted samples (and expressing the result as CFU per mL) estimates how many living cells were in the original culture. It does not measure dead cells or total cell count, and it isn’t just about the number of colonies alone without accounting for dilution. It also isn’t about fragmentation.