CFU remains the key variable in assessing microbiological quality. However, even the pharmacopeia criticize the validity of this method.
The USP considers the CFU value to be more of an estimate than an exact figure as, for example, only 0.1–1% of all germs are counted as CFU in potable water. As a result, it is posited that CFU should not be considered the only measure for assessing microbiological quality. According to Ph. Eur., the applicable threshold values were established without quantitative measurement. As an example, the—randomly—determined acceptable value of 10 CFU / 100 mL for WFI has become the norm.
It can be seen: even the pharmacopeia clearly see the weaknesses and limits of conventional methods of measuring CFU. For this reason, it is now time to use cutting-edge technologies that can offer game-changing advantages to quality managers and microbiologists.