"
Imperial College London/Notebook/11 September 2009
From 2009.igem.org
(Difference between revisions)
| (5 intermediate revisions not shown) | |||
| Line 6: | Line 6: | ||
====Protocol considerations==== | ====Protocol considerations==== | ||
| - | Using spectrophotometer at 600nm | + | *Using spectrophotometer at 600nm |
| - | Blanks are all the relevant carbon sources, but subsequently realised that all blanks were roughly the same (within 0.03) | + | *Blanks are all the relevant carbon sources, but subsequently realised that all blanks were roughly the same (within 0.03) |
| - | Therefore, subsequent readings= blank+ 6 sample | + | **Therefore, subsequent readings= blank + 6 sample |
| - | Overnight culture had OD of 1.64. | + | *Overnight culture had OD of 1.64. |
| - | 800ul was put into each sample of 40ml~ 0.033 OD | + | **800ul was put into each sample of 40ml~ 0.033 OD |
| - | ie same initial OD | + | **ie same initial OD |
| - | Grown in 6 separate 50ml falcon tubes and shaking in incubator at 28 degrees Celsius | + | *Grown in 6 separate 50ml falcon tubes and shaking in incubator at 28 degrees Celsius |
| - | 1ml taken out at 1 hr intervals from the falcon tube and placed into spectrophotometer | + | *1ml taken out at 1 hr intervals from the falcon tube and placed into spectrophotometer |
====Results==== | ====Results==== | ||
[[Image:Diauxic growth.jpg]]<br> | [[Image:Diauxic growth.jpg]]<br> | ||
| - | [[Media:Diauxic | + | [[Media:Diauxic growth_11-09.xls| Download raw data]] |
====Conclusions==== | ====Conclusions==== | ||
| - | + | *Glucose, as expected, had the highest growth rate | |
| + | *Cells under all secondary carbon source conditions appear to stop growth at 6 hrs. | ||
| + | ** Therefore, we can suggest that the switch point is after 6 hours | ||
| + | **However, further data at longer time points are required to confirm this. | ||
| + | |||
| + | ====Suggestions/Improvements==== | ||
| + | * Longer duration of taking readings (but currently limited to 8hrs- length of a day and multiplate reader evaporation) | ||
| + | * Earlier switch point can be induced by adding a smaller concentration of glucose to media | ||
| + | **suggested 0.01% Glucose for next experiment (we predict it will take around 2 hours) | ||
{{Imperial/09/TemplateBottom}} | {{Imperial/09/TemplateBottom}} | ||
Latest revision as of 16:44, 4 October 2009
Contents |
Testing
Diauxic growth 11th Sep
Protocol considerations
- Using spectrophotometer at 600nm
- Blanks are all the relevant carbon sources, but subsequently realised that all blanks were roughly the same (within 0.03)
- Therefore, subsequent readings= blank + 6 sample
- Overnight culture had OD of 1.64.
- 800ul was put into each sample of 40ml~ 0.033 OD
- ie same initial OD
- Grown in 6 separate 50ml falcon tubes and shaking in incubator at 28 degrees Celsius
- 1ml taken out at 1 hr intervals from the falcon tube and placed into spectrophotometer
Results
Conclusions
- Glucose, as expected, had the highest growth rate
- Cells under all secondary carbon source conditions appear to stop growth at 6 hrs.
- Therefore, we can suggest that the switch point is after 6 hours
- However, further data at longer time points are required to confirm this.
Suggestions/Improvements
- Longer duration of taking readings (but currently limited to 8hrs- length of a day and multiplate reader evaporation)
- Earlier switch point can be induced by adding a smaller concentration of glucose to media
- suggested 0.01% Glucose for next experiment (we predict it will take around 2 hours)
