To understand the functional integrity of the whole living organism, it is important to have a clear understanding of the interactions between individual cells and a single molecule within these cells. With the latest biomolecular/cellular imaging technology, researchers are focusing on investigating such biological interactions at both molecular and cellular levels. This involves direct imaging of the “presence” of single molecules and individual cells as well as the use of real-time imaging of dynamic, reversible biological signaling “events” such as protein-protein interaction, protein modification and intracellular calcium changes. Moreover, this imaging technology can be combined with the protein manipulation techniques to elucidate the functional contribution of these dynamic interactions and signal transduction events in the whole living organism.

1. Temperature

Most mammalian cells grow at 35-37℃. If the temperature is not optimally controlled, the cell growth can be largely compromised. High temperature is more detrimental since it results in an immediate cell death. Therefore, maintaining the temperature within an optimal range is very important for cellular imaging. When the imaging with a high numeric aperture lens, it is necessary to control the temperature of the objective.

2. pH

Correct pH is crucial for the cultured cells to maintain the normal physiological states and thus remains viable for a long time. The pH of the medium should be maintained around pH 7.4. The bicarbonate buffer system is the most widely used in the cell culture. The pH depends on the level of CO₂. Thus, the CO₂ level should be maintained during the cell imaging.

3. Humidity

All incubator systems should maintain the internal humidity to prevent the medium evaporation. The evaporation causes the accumulation of the cell metabolites and medium constituents that will eventually impair the cell growth.