Laboratory incubators provide a controlled, contaminant-free environment for safe, reliable work with cell and tissue cultures by regulating conditions such as temperature, humidity, and CO2. Microbiological incubators are used for the growth and storage of bacterial cultures.
A Bacteriological incubator
Louis Pasteur used the small opening underneath his staircase as an incubator. Incubators are also used in the
poultry industry to act as a substitute for hens. This often results in higher hatch rates due to the ability to control both temperature and humidity. Various brands of incubators are commercially available to breeders.
The simplest incubators are insulated boxes with an adjustable heater, typically going up to 60 to 65 °C (140 to 150 °F), though some can go slightly higher (generally to no more than 100 °C). The most commonly used temperature both for bacteria such as the frequently used
E. coli as well as for mammalian cells is approximately 37 °C (99 °F), as these organisms grow well under such conditions. For other organisms used in biological experiments, such as the budding yeast
Saccharomyces cerevisiae, a growth temperature of 30 °C (86 °F) is optimal.
More elaborate incubators can also include the ability to lower the temperature (via refrigeration), or the ability to control humidity or
CO2 levels. This is important in the cultivation of mammalian cells, where the relative
humidity is typically >80% to prevent evaporation and a slightly acidic
pH is achieved by maintaining a CO
2 level of 5%.