Optimizing the incubator environment

The primary function of an incubator in the ART lab is to provide stable conditions for the embryo, and create an environment where pH, temperature and air quality are tightly controlled.

Temperature control

Maintaining a constant temperature of 37°C is a top priority during all stages of culture.

  • Cooling oocytes causes spindles to depolymerize.² Once re-warmed, there is a risk of reformation failure, wrongful reattachment of the chromosomes and subsequent aneuploidy of the embryo
  • Exposing early embryos to temperature changes may upset cellular metabolism, membrane stability and transport processes³
  • Strictly monitor the incubator temperature, which can be more easily controlled in incubators with chambers for individual patients
G210 Incubator

Gas phase and pH

Culturing gametes and embryos in the right pH is crucial. As CO2 concentration helps regulate the pH of the culture medium, it is essential that the level of CO2 in the incubator is known and consistent.

  • Ensure that the CO2 level in each incubator is independently validated
  • Do not rely on the CO2 setting in the incubator; the relationship between CO2 and pH is dependent on the bicarbonate level of the media, as well as the lab’s altitude¹

Oxygen (O2) concentration

Lowering the O2 concentration in the culture environment has repeatedly been found beneficial for embryo development and outcomes,8 most notably when  reduced throughout the entire culture period (i.e. to the blastocyst stage).9-11

  • Monitor and regulate incubator O2 concentrations for optimal embryo development

Air quality

Embryos are sensitive to environmental toxicants, particularly to volatile organic compounds (VOCs). Establishing good air quality, ideally via chemical air filtration, is essential to have an optimal culture system.5-7

  • Ensure incubators are fitted with an in-line HEPA gas filter; enclosed incubator environments may have concentrated VOC levels several times higher than the ambient air
  • Ensure cleanliness of the lab air by either installing HEPA filters or using mobile air filtration units

Humidity and osmolality

Many incubators regulate humidity to avoid media evaporation during culture, which may cause harmful rises in medium osmolality. However, culture in a nonhumidified environment is possible if the culture dishes are covered with adequate amounts of oil overlay.4