An incubator is a device designed to grow and maintain microbiological or cell cultures. It creates and regulates optimal conditions, including temperature, humidity, and atmospheric composition (such as CO₂ and oxygen levels), to support cell growth. Incubators are essential tools in cell biology, microbiology, and molecular biology, commonly used for culturing bacterial and eukaryotic cells.
The incubator consists of a chamber with regulated temperature controls. Some models also regulate humidity, gas composition, and ventilation within the chamber.
The simplest incubators are insulated boxes equipped with adjustable heaters, typically capable of reaching temperatures between 60 to 65°C (140 to 149°F). Some advanced models can achieve slightly higher temperatures, generally up to 100°C. For most experiments, the commonly used temperature is approximately 37°C (99°F), as it provides optimal growth conditions for organisms like E. coli and mammalian cells. For organisms such as the budding yeast Saccharomyces cerevisiae, a growth temperature of 30°C (86°F) is ideal.
More advanced incubators offer additional features like refrigeration to lower the temperature or mechanisms to control humidity and CO₂ levels. These features are particularly important in cultivating mammalian cells, where maintaining a relative humidity level above 80% prevents evaporation. Additionally, a slightly acidic pH environment is achieved by maintaining a CO₂ level of 5%.