What issue arises from cells in culture settling to the bottom of the tube or cuvette?

When cells in culture settle to the bottom of a tube or cuvette, it can lead to inaccuracies in the results of experiments. This settling can create a situation where not all cells are evenly distributed throughout the medium. If measurements, such as absorbance or cell counts, are taken without proper resuspension of the cells, the results may reflect a non-representative sample of the cell population. For instance, if cells settle, any optical measurements could indicate a lower or higher concentration than actually exists in the entire volume of liquid. This could lead to flawed data interpretations, affecting everything from cell viability assessments to the analysis of metabolic activity. Addressing this settling by thoroughly mixing the cell culture before measurements is essential to ensure accurate and reliable results.