The right conditions and techniques provide a range of effective storage options
After all of the work that goes into creating a cell or tissue culture, scientists depend on excellent storage methods. Otherwise, the cell or tissues just die. Creating the right storage environment for cultures, though, takes the right technology, and a few tips on use.
The need for culture storage arose from some of the first cultures. Even in the 1800s, scientists found ways to create an environment that supports culture survival and even growth. It just takes a bell jar and a candle. Apply a sealant, like petroleum jelly, to the rim of the bell jar, and cover the culture and a lit candle with the jar. The flame uses the oxygen inside the bell, which effectively increases the concentration of carbon dioxide. Then, by adding heat in some way, this makes a very simple CO2 incubator.
Various gases can be controlled in a modern culture incubator to create the most physiological environment for the cells or tissues. One of those gases is still CO2, which is often controlled to keep the samples at the desired pH. With sodium bicarbonate (NaHCO3) in the growth media, it stays in equilibrium with H2O + CO2 in the incubator, and the buffering controls the pH.
Today’s scientists, though, don’t need a bell jar and candle to control a culture’s environment.
Culture keepers
To culture a variety of cells or tissues, scientists need the ability to fine-tune various parameters. According to NuAire (Plymouth, MA), its “CO2 incubators offer a finely controlled in-vitro growth environment.” The company adds about its incubations: “When properly employed, tissue cell growth is neither stunted nor ceased through desiccation.”
The proper use of these incubators includes adjusting the temperature, humidity, and CO2 level. Platforms are available with an air or water jacket for direct or indirect heat, respectively. As NuAire points out: “Advanced gas control systems are available to create precise environmental conditions for your protocols requiring hypoxic conditions.”
Instead of keeping cultures warm, some applications require cold—extreme cold. For long-term storage, scientists freeze cells or tissues. In addition to the right method, this depends on a reliable freezer. “NuAire’s Upright Ultra-Low Temperature Laboratory Freezers provide the best, most stable sample storage available,” the company notes. Scientists can select the best size for their –80 °C needs.
Avoiding user error
Even with the best technology, any user can find many ways to kill cultures. To avoid that, take a look at NuAire’s “Guide to Proper CO2 Incubator Use and Preventative Maintenance". As this guide notes: “Researchers depend on both the incubator and the lab manager responsible for operation and maintenance of the incubator.”
To keep cells or tissues in the best environment, an incubator needs to be clean. That takes regular maintenance. NuAire’s guide also notes that “contamination due to human error or from the surrounding environment also poses risks.”
Actually, keeping an incubator clean starts with the very first step in owning one—choosing its spot in the lab. As NuAire’s guide suggests, “Locate the incubator away from strong air currents such as air conditioning vents that may be a source of contaminants ….”
By selecting the best incubator for a lab’s needs, placing it in a good location, and using and maintaining it properly, scientists can grow many kinds of cells and tissues. Those samples can be kept viable for even longer in a freezer that fits a culture’s needs. No matter what, scientists can skip the bell jar-and-candle technique.
Mike May is a freelance writer and editor living in Texas. He can be reached at [email protected]