Antifoam 204 is a polyether oil that pops bubbles and prevents stable foam formation in our SparkleCell high density E. coli cultures. It is not possible to use SparkleCell without it. If you ever forgot to add it, your SparkleCell would over-bubble within seconds and spill most of the culture. Please see the last product image for a visualization of Antifoam 204's remarkable efficacy.
If you are purchasing a SparkleCell for the first time, you do not need to buy this. All SparkleCell models ship with plenty of Antifoam 204 to get you started.
The recommended amount to use is 1 ml antifoam per 1 L culture (0.1% v/v). That amount is approximate. It is perfectly safe to eyeball it, using dispensing mechanisms built into the bottles. If your foam collapses, you are safe. It will stay that way throughout your culture. Unless something changes. For example if you are using solid media components, you'll need to wait until they're fully dissolved until you can be sure that you're safe. As media components dissolve over time, the viscosity and bubble formation continues to increase. Also, Antifoam 204 is temperature-dependent:
One of the things to know about Antifoam 204 is that its efficacy is temperature dependent. If you lower the temperature during induction of protein expression, be prepared to watch your SparkleCell attentively and add more Antifoam as needed.
- The recommended amount, 0.1% will support a temperature drop to 28C.
- If you drop the temperature even lower, you'll probably need to add more Antifoam.
- If the temperature stays at 37C at all times, less antifoam will be OK.
Certain other antifoams might not work as well. We tested cheaper solid particle suspensions "Antifoam A", and found them initially very effective, but they become inactivated once E. coli growth picks up. It's possible to get through a production run with Antifoam A, but above OD600 = 10, the particles needed to be replenished at least every hour. Isopropanol spray can be used to pop bubbles on impact, but won't prevent their formation for any length of time. Antifoam 204 does not become inactivated even during 24-hour culture periods or longer.