What is an Incubator?
An incubator is a device used to grow and maintain microbiological cultures or cell cultures. The incubator maintains optimal temperature, humidity and other conditions such as the CO2 and oxygen content of the atmosphere inside. Incubators are essential for much experimental work in cell biology, microbiology and molecular biology and are used to culture both bacterial and eukaryotic cells.
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 CO2 level of 5%.
- General types of incubators
There are many different types of incubators, and the most commonly used are the following:
- Standard incubators: These incubators can be gravity or fan assisted convection and their range of temperature is from ambient to a maximum of 80°C or 100°C
- Cooled incubators: These incubators work at temperatures close to or below ambient temperature
- Humidity incubators: These incubators control both, temperature and humidity, thanks to a refrigeration system rather than by direct heating.
- CO2 (carbon dioxide) incubators: These incubators are widely used in Biological and it is used when it is necessary to maintain a determined percentage of carbon dioxide in the incubator. The level of CO2 is controlled by a thermal conductivity sensor or infra-red sensor. The humidity is usually obtained from a tray of water which is constantly evaporating.
- Shaking incubators: These incubators shakes in a temperature controlled atmosphere. There are different size of this type of incubators, with a range of temperature from ambient or refrigerated.
- Hybridisation incubators or hybridisation ovens: These incubators hold different sizes of hybridization bottles and rotate them at a set speed to enable hybridization in molecular biology.
Natural vs Forced Convection
Two types of convection or air flow are usually available with incubators. Natural Convection (Gravity flow) incubators have no fans or mechanism to move the air; the circulation is based on the laws of physics (hot air rises, cool air falls). An active or forced air flow will enhance the temperature uniformity throughout the chamber, but can also create a drying effect over time. Some forced air incubators have an adjustable fan so that the negative effects of either option can be moderated.
What is a Safety Thermostat
After exceeding the safety threshold, the thermostat opens the circuit and automatically disconnects power to the heating device. re-switching of the heating device after the manual unlocking of the thermostat.
How to work out size of incubator required from customers bottle sample size?
Length of shelf / bottle diameter+4mm = X (round number to smallest integer)
Width of shelf / bottle diameter+4mm = Y (round number to smallest integer)
X*Y = number of bottles per shelf
Total internal Height of incubator / (Height of Bottle + shelf height + clearance)
= No of Shelves required
Information required to quote on an Incubator
- What size incubator do you require?
- What temperature range will you be working at?
- How Many Shelves / Maximum Weight per shelf
- Do you require an Inner Glass Door?
- Do you require Temperature Data Logging?
- Do you require Programmable Temperature Control?