"
Team:NTU-Singapore/Wetlab/Protocols
From 2008.igem.org
|
I) MATERIALS:
1) Preparation of AI-2:
Pure AI-2 is very difficult to harvest or synthesize. However, as a quorum sensing messenger, AI-2 is present in intercellular medium at considerable amount. In this project, AI-2 was indirectly harvested by obtaining cell supernatants at different time points of cell growth. Glucose was added to the growth medium as it promotes AI-2 production significantly (Liang Wang, 2005).
A colony of E. coli W3110 was grown overnight in LB for 16 hours at 37 oC. The overnight culture was then diluted in LB plus 0.8% glucose to an optical density at 600 nm (OD600) of 0.02. The cells were incubated at 37oC with shaking at 225 rpm in 500ml Erlenmeyer flask. Cell aliquots were removed at each time point for measurement of the OD600. The measured values were shown in the following table:
| Time (hrs) | OD of W3110 |
| 0 | 0.002 |
| 1 | 0.047 |
| 2 | 0.112 |
| 3 | 0.341 |
| 4 | 0.628 |
| 5 | 0.921 |
| 6 | 1.032 |
| 7 | 1.172 |
| 8 | 1.252 |
