Innova® CO-48 Incubator

When shopping for mammalian cell culture incubators, there are many models to choose from with many different options. Depending on the size of the incubator and the options, prices can range from about $2000 over $15,000. The Innova CO-48 model incubator from New Brunswick Scientific is a small (1.7 ft³ or 48 L) incubator that comes at a reasonable price (less than $5000).

The CO-48 has a seamless, stainless steel chamber surrounded by a direct heating system, which provides an even temperature throughout the chamber. The door of the incubator is heated independently with the door temperature set several degrees higher to prevent condensation. With the humidity tray in place, chamber humidity should remain around 95%. By turning the humidity control adjustment knob on the right side of the incubator, the user can increase the relative humidity by about 2%. In addition to the standard solid-state infrared CO₂ sensor, an oxygen sensor and a humidity sensor can also be purchased for the CO-48.

Set-up is easy. Once the incubator is in place with power and CO₂ hooked up, all that remains is to program the incubator with the temperature and CO₂ set points. This is easily done on the CO-48’s touchpad screen. In addition to setting the temperature and CO₂ levels, the incubator can be programmed to alarm either or both visually and audibly if the set points are not reached within a given amount of time. Another nice feature of the Innova CO-48 is the datalogger screen. On this screen, the user can choose to view alarm events, as well as graphical representations of CO₂, temperature and door openings over an extended period of time, among other options. There are additional settings, such as a CO₂ auto-zero function and a security function to prevent just anyone from changing the incubator settings.

We purchased two CO-48s several months ago. Our reasoning for purchasing them was 2-fold. First, the volume of cell culture we perform is small enough that the CO-48’s smaller size was adequate for our needs. Secondly, since we use both primary cell cultures and established cell lines, we wanted to keep the two populations separated, thereby reducing the risk of contamination. Also, the cost of the CO-48 was reasonable enough that purchasing two of them fit within our budget. One of the best things about the CO-48s has been that we have been able to fit both of them in a smaller space than our original incubator (even though they are not stackable) without purchasing a $450 stand.

Although the idea of having 2 “personal” sized incubators seemed like a good one, the reality has not been as rosy as we had hoped. The major problem we have encountered is the inability to maintain humidity in the CO-48. We have actually had several small volume cultures dry out. We have found that under normal operating conditions (5% CO₂ and 37^ C), the relative humidity remains between 88% and 90% even after 14 undisturbed hours. Our concerns were very quickly addressed by New Brunswick but they were unable to successfully fix the problem. Finally, after 3 months of this problem, they talked to the manufacturer and came up with a makeshift solution. I was told to take the feet off the incubator and place it directly on the cabinet top. This would reduce the airflow under the incubator, directing all the heat generated in the bottom of the incubator up into the water pan thereby increasing the relative humidity. Our humidity level has now reached 95% but once the door is opened, the humidity rapidly decreases and takes about 2.5 hours to come back up to 95%. Although the CO-48 has some great features and a very reasonable price, I would not buy this model again.

J. Jason Clark, MS
Research Assistant III
University of Iowa
Otolaryngology