Heratherm Advanced Protocol Microbiological Incubators by Thermo Fisher Scientific

Gravity convection introduces heated air into the bottom of the incubator and gravity causes the warmer air to rise and be distributed throughout the incubator. With less air being displaced, there is no need for a fan because gravity provides the force needed to distribute the warm air that gently heats samples. This convection mode prevents samples from drying out during incubations. Gravity convection technology is ideal for incubation of bacterial and eukaryotic cell cultures, but is limited by the degree to which air can be heated and the time it takes for an incubator to recover after the door is opened.

Mechanical convection utilizes a fan that delivers heated air throughout the incubator creating a uniform temperature distribution throughout the unit. This method provides optimal temperature uniformity and stability due to the rapid distribution of air, which is ideal for bacterial cultures. In addition, mechanical convection is capable of quickly warming samples that have been transferred directly from the refrigerator to the incubator. Many laboratories choose mechanical convection incubators during sample drying to prevent the evaporation of growth media.