EDITORIAL: In vitro experiments with primary mammalian cells: To Pool or not to Pool?

There are various strategies that can be adopted when performing in vitro experiments with primary cells such as mesenchymal stem cells. It is generally accepted that multiple donors need to be investigated to take into account donor to donor variability; this is especially critical when investigating primary human cells. However, increasingly it is being seen that studies are pooling the cells from multiple donors prior to performing the experiment. This has obvious advantages but also many disadvantages, the greatest being loss of statistical power. This loss of statistical power is the reason why the pooling of primary cells for experiments is not to be recommended.