Incubator word comes from the Latin word “incubare” which means to “brood“. The incubator is designed as a chamber of controlled temperature, atmosphere and humidity for the purpose of maintaining live organisms in an environment suitable for their growth. Among its most common uses are incubation of bacteriological, viral, microbiological and cellular cultures; determination of the biochemical demand for oxygen (BOD) and biological storage. Incubators vary in complexity and design.

What is an Incubator?

An incubator is a laboratory device that keeps optimal conditions—such as temperature, humidity, and carbon dioxide (CO₂) levels—to support the development of organisms like bacteria, fungi, and mammalian cells. It simulates the conditions of the human body or other specific environments to allow biological processes to occur efficiently and safely.

Incubation Chamber:

Incubators are used for maintenance of constant internal environments such as temperature, humidity and a particular gas concentration in a limited space called incubation chamber. The incubation chamber is usually divided into convenient spaces by adjustable, perforated metal shelves. The chamber may be provided with a glass door to provide additional protection against leak of atmospheric conditions. It is also provided with sensors for temperature, humidity and gas concentration that are connected to display and adjustment knobs or buttons on the exterior controlled by appropriate microprocessors. In modern incubators the displays are of digital type. Some incubators are provided with an alarm system that sounds if the atmospheric conditions in the chamber deviate from the preset values.

What are the key features of a laboratory incubator?

• Control of Temperature
  • The majority of incubators keep the temperature at body temperature, or about 37°C, which is perfect for cultivating mammalian cells or human infections.
• Control of Humidity
  • Sufficient humidity keeps samples from drying out and promotes healthy cell development.
• Regulation of CO2
  • Particularly for mammalian cell cultures, the carbon dioxide content in CO₂ incubators is maintained at roughly 5% to replicate the natural cellular environment.
• Sterile Environment
  • Using UV lamps, HEPA filters, or antimicrobial coatings, the incubator is made to reduce contamination.
• Monitoring Systems and Alarms
  • Sensors and alarms are built into contemporary incubators to identify any departure from the established specifications.

What are the common types of Incubator?

1. Simple incubator:

This type of incubator control only the temperature in the incubation chamber. Simple incubators are the most commonly used incubators in the laboratory for bacterial cultures and incubation of other constituents.

2. Anaerobic Incubators:

2. Anaerobic incubators: In these type of incubators, oxygen (O₂) inside the chamber is swapped with nitrogen (N) to provide an anaerobic atmosphere. These are commonly used to culture anaerobic microorganisms

3. CO2 Incubators:

In CO2 incubators, the air inside the incubation chamber is changed with a mixture of 5-10% CO2 gas in air. This can be attained by release of CO2 gas in the chamber or by release of the required mixture. These are commonly used to culture some microorganisms and tissue cells.

4. Cell Culture Incubators:

Cell Culture incubators are the most sophisticated incubators. Entire atmosphere inside the incubation chamber is controlled to provide exact temperature, humidity and CO2 gas concentration. These are used for culture of cells and tissues.

5. Shaking Incubator

A shaking incubator is use to shake the samples simultaneously during incubation. It’s primarily used in biotechnology and microbiology for growing and maintaining microorganism cultures. This incubator is commonly use to promote aeration and even distribution of nutrients within the culture, crucial for optimal growth with the shaking action.

Routine Maintenance And Use Of The Incubator

The general operation and routine maintenance for Incubators are featured next. The specific procedures must be followed according to the recommendation of each manufacturer.

Recommendations for operation

1. Do not use an incubator in the presence of flammable or combustible materials as components inside of this equipment could act as ignition sources during operation.
2. Avoid spilling acid solutions inside the incubator. These cause the incubation chamber material to deteriorate. Whenever possible, try to use substances whose pH is neutral. Avoid incubating substances generating corrosive vapours.
3. Avoid placing receptacles on the lower cover which protects the resistive heating elements.
4. Use personal protective elements when using the incubator: safety eyeglasses, gloves, tongs for placing and removing containers.
5. Avoid staying in front of an open incubator. Some substances emit vapours that should not be inhaled.
6. Calibrate the incubator where it is installed to establish its uniformity and stability.
7. Verify the operational temperature of the incubator in the morning and evening hours, with certified calibrated instruments (thermometer, thermocouple, etc.).
8. Register in the appropriate document or form each excursion detected in the incubator (i.e. temperature, humidity or CO2 level) and any corrective action necessary.
9. Daily: Verify that the temperature in the incubator does not vary more than one degree centigrade (+/– 1 °C). Record temperature.
10. Add a non-volatile microbial inhibiting agent if water is needed inside the incubator to maintain a certain level of humidity.

Cleaning recommendations for incubators

Clean cell culture or bacterial incubators regularly, at least every 14 days and after any infectious material spill, using appropriate disinfectants.

1. Disconnect the incubator before initiating the cleaning processes.
2. Use non-abrasive cleaning agents: a piece of cloth dampened with mild detergent for cleaning easily reached interior and exterior surfaces.
3. Avoid contact between cleaning agents and electric elements.
4. Wait until the incubator is dry (free of humidity) before connecting it again.

Applications of Incubators

• Microbiology: Use for bacterial and fungal colonies growth, identification and testing.
• Cell Culture: Growing and maintaining mammalian cells for research proposes or medical applications.
• Genetics: Incubating DNA samples during PCR (polymerase chain reaction) and hybridization.
• Pharmaceutical Testing: Evaluating the effects of drugs on cells or microbes.
• Environmental Studies: Assessing pollution levels in water or soil samples.