Incubator: Introduction, Principle, Handling Procedure, Types, Uses, and Keynotes

Introduction of Incubator

Bacteriological incubator (Ambassador Brand)
Fig. Bacteriological Incubator (Ambassador Brand)-Upper Part
 Bacteriological Incubator (Ambassador Brand)-Lower Part
Fig. Bacteriological Incubator (Ambassador Brand)-Lower Part
Microbial specimens inoculated culture media in Incubator
Fig. Microbial specimens inoculated culture media in Incubator
Chitranas Bacteriological Incubator
Fig. Chitranash Bacteriological Incubator

The incubator is an electrical device in which the incubation process is performed which conditions an enclosure to a predetermined temperature since it provides and maintains all artificial optimal conditions for the growth of microbial culture as well as cell and tissue culture.

Principle and Working of Incubators

Incubators work on the principle of thermo-electricity. It has a thermostat that maintains a constant temperature by creating a thermal gradient. When any conductor, an electrically-controlled switch used for switching an electrical power circuit subjected to a thermal gradient, generates voltage called a thermoelectric effect. As power is supplied to the circuit predetermined temperature (37˚C) is set in the incubator. This temperature is maintained by the compatibility operation of the temperature sensor, the temperature controller and the temperature contactor are major components.

When the power is off, current flows into the system thereby energizing the contactor that powers the bulbs which serve as heating elements to the system, the fan ensures the Distribution of hot air in the entire system. When the temperature in the system gets to desirable i.e. 37˚C the digital temperature controller sends an electrical signal to the contactor which is de-energized thereby switching off the heaters temporarily. Also when the temperature reduces beyond the desired temperature. The contractor will be energized again thus switching on the system.

Types of Incubators

The most common types of incubators are –

  1. BOD incubators
  2. Bacteriological incubators
  3. CO2 incubators

The main difference between these two types of incubators is due to temperature. BOD stands for biological oxygen demand and it is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic materials present in a given sample at a certain temperature over a specific time period.

 Bacteriological Incubator (Scientific Product)-Lower Part
Fig. Bacteriological Incubator (Scientific Product)-Lower Part
 AST Plates, Microbial specimens inoculated culture media ( Blood agar, MacConkey medium, Chocolate agar), Biochemical tests media in Bacteriological Incubator
Fig. AST Plates, Microbial specimens inoculated culture media (Blood agar, MacConkey medium, Chocolate agar), Biochemical tests media in Bacteriological Incubator

Bacteriological Incubators

This type of incubator is used mainly in laboratories usually for the growth of bacteria. A constant temperature set according to the requirement is possible because of having a thermostat that maintains it. Accurate temperature can be visible on the thermometer fixed on incubators. Most of the incubators are programmable and do not need trial-and-error temperature settings. They only hold a heating system that maintains the temperature for the growth of bacteria. Due to the absence of a cooling system, these incubators are affected by the temperature of the surrounding environment.

BOD incubators (Low-Temperature Incubators)

These types of incubators are often called low-temperature incubators used for the growth of fungi i.e. yeast and mold as they require a low temperature to grow. These types of incubators are called BOD (Biological oxygen demand) incubators because in biological oxygen demand testing there is a need for a low temperature of around 20-25˚C.  So, don’t confuse the term because the purpose of BOD incubators is also the same as bacteriological incubators.


Inside incubators, also known as gassed incubators, an atmosphere is created that is as natural as possible to develop cell and tissue cultures. This way of cultivating living organisms is called in vitro and is the main application for CO2  incubators.

The following parameters are crucial for cell cultivation:

  • COlevel
  • Temperature
  • Humidity
CO2 Incubator (New Brunswick)
Fig. CO2 Incubator (New Brunswick)
Blood agar and chocolate agar  incubated CO2 Incubator
Fig. Blood agar and chocolate agar in CO2 Incubator
Sanyo CO2 incubator with CO2 cylinder
Fig. Sanyo CO2 incubator with a CO2 cylinder
Sanyo CO2 incubator
Fig. Sanyo CO2 Incubator
 Sanyo CO2 incubator loaded with microbial specimens inoculated culture media
Fig. Sanyo CO2 incubator loaded with microbial specimens inoculated culture media

Handling Procedure of Incubators

  1. Make ready material of interest (e.g. microbes, specimen inoculated agar plates, etc.).
  2. Switch on the incubator and check the temperature of interest (and also the CO2 level in case of using a CO2 incubator).
  3. Place the material of interest and wait for the required incubation period.
  4. Take out and finally switch off the incubator.

Uses of Incubators

Incubators use for the growth of microorganisms in many fields, including medical, pharmaceuticals, agricultural, environmental, food, and industrial microbiology, public health, basic research, and education. Whereas COincubators are most frequently used in medical research and the pharmaceutical industry. However, they also provide sterile conditions for cultivation in other fields where cells must grow in a completely germ-free environment.

  • COincubators for tissue-engineered products
  • CO incubators for in vitro fertilization
  • CO incubators in diagnostics
  • CO for developing biosensors
  • CO incubators in cancer research


  1. Calibration of incubators: Calibration is done by performing temperature monitoring by using a data logger with the sensor.
  2. From what point is an incubator ready for use? In total, the incubator goes through three steps during validation: and they are-
  • Installation Qualification
  • Operational Qualifications and
  • Performance Qualifications
Rotating Incubator
Fig. Rotating Incubator



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