An incubator is an enclosed device that maintains controlled environmental conditions, such as temperature, humidity and sometimes gas composition, to support the growth or development of biological specimens or cultures.
Explanation
Laboratories use incubators to provide stable conditions that mimic natural environments so that microorganisms and cells can replicate. Basic microbiological incubators regulate temperature, often around 35–37 °C, to encourage bacterial growth and include fans and insulation to ensure uniform heating. More specialized units, such as CO2 incubators, incorporate sensors and gas regulators to maintain a humid atmosphere with about 5 % carbon dioxide, which buffers the pH of bicarbonate-based media for mammalian cell culture. Anaerobic incubators or glove boxes control oxygen levels by flushing with nitrogen or other gases to support obligate anaerobes.
Other incubator designs serve different purposes. Shaking incubators combine temperature control with orbital agitation to improve aeration and nutrient mixing in liquid cultures for fermentation or protein expression. Egg incubators used in agriculture and zoology maintain constant warmth and humidity to develop embryos outside the parent. Neonatal incubators in clinical settings regulate temperature and humidity for premature infants, although these are distinct from laboratory incubators. Regardless of type, proper calibration and regular disinfection are essential to prevent contamination and ensure that set points match actual conditions. Modern units often include digital displays, alarms and data logging to aid quality control and compliance with laboratory standards.
Example uses and facts
- Clinical laboratories incubate throat swabs and urine samples at 35–37 °C for 18–48 hours to recover pathogens such as Streptococcus pyogenes or Escherichia coli.
- Fungal cultures, including Candida species, may be incubated at 25–30 °C to encourage yeast or mould growth.
- Mammalian cell lines like HeLa or HEK293 require a CO2 incubator with 5 % carbon dioxide and high humidity at 37 °C to maintain pH and viability.
- Chicken eggs hatch after about 21 days when kept at around 37.5 °C with controlled humidity and periodic turning.
- Shaking incubators are used to culture bacteria for recombinant protein production, providing both warmth and agitation to maximize growth.
Incubators are essential tools in microbiology, biotechnology, agriculture and medicine. By controlling environmental variables they enable reproducible growth of organisms and cells and support research, diagnostics and production processes.
Related Terms: incubation, CO2 incubator, cell culture, temperature control, microbial growth