What Seems Best for Incubation is Not Always Best for Handling
Most, but not all, cell culture media contain carbonate-based buffers which work with elevated gaseous carbon dioxide levels in the incubator to stabilize cell culture pH (see figure). Carbonate-based buffers are present in vivo and so seem like an obvious choice for physiologically relevant incubation conditions. However, carbonate-based buffers can create non-optimal conditions for cultures during cell culture handling outside of the incubator. The critical cell parameters of temperature and carbon dioxide levels can affect carbonate buffered cell media.