What is a potential consequence of measuring growth by turbidity in cell cultures?

Measuring growth by turbidity in cell cultures provides a quantitative estimate of cell density based on the cloudiness of the culture. However, a potential consequence of this method is that dead cells can contribute to turbidity. This is significant because turbidity does not only result from live, metabolically active cells; it can also be influenced by cell debris and dead cells that still scatter light. Therefore, if a culture exhibits high turbidity, it is challenging to determine how much of that turbidity is due to viable cells versus dead ones. This can lead to misleading interpretations about the health and growth status of the culture.

In contrast, relying solely on turbidity measurements without additional assessments can result in inaccuracies regarding the actual living cell count, as viable cells may not always be the primary contributors to observed turbidity. Thus, it is essential to combine turbidity measurements with other methods, such as viability assays or colony-forming unit counts, to accurately assess cell growth and health.