Imperial College London/Notebook/10 September 2009

Protocol considerations

 * Multiwell plate reader
 * Using script IGEM Abs, taking readings every 30 min


 * Overnight culture cells were grown. (normal Top10)
 * A volume of overnight cells were diluted into fresh M9 media


 * 1ml of each secondary carbon source media (in M9) was prepared
 * 200ul was added to 96 well plate as blank


 * Write out well plate layout and do test runs of script *IMPORTANT*


 * After about 5 hours, when cells were at a high enough OD (cloudy), cells were added 1:20 into the media
 * the cells and media were mixed well, and then 200ul was added into 96 well plates


 * The plate reader was run overnight

Results
[[Media:Diauxic growth_10-09.xls| Download raw data]]

Conclusions

 * Cells in Maltose grow slower, while the growth rate in the other secondary carbon sources are similar
 * The cells appear to have continuous growth up till 7 hours. However, after that, the results become random.  This is probably due to the evaporation problem

Suggestions/Improvements

 * There is an initial spike. This should be a multiplate reader problem
 * Suggestion is to use a higher starting OD ~ 0.5 or 1


 * The diauxic growth is using normal cells which grow on Strep. However, the growth profile might be significantly different on Amp (for our testing construct)
 * Therefore, use a cell with an Amp construct that is not expressed


 * Try not to use any readings from the multiplate reader after around 8 hours


 * To arrive at the switch point faster, 0.01% Glucose will be used instead for next experiment