Growth Curve - Cannot pull off 24 hrs straight (Oct/04/2007 )

Hello friends,

I need to do simultaneous growth curves of a transformant and wild type. I have family responsibilities such that i cannot pull off more than 12 hrs worth of readings. I was wondering if someone has any ideas on how to do the curve with interruption but minimal error in results.

Thanks for taking the time.

Ideal solution: - get a machine. There are automated optical density readers (with in built shaker and incubator). Such a machine can be set to collect readings after every preset period of time. Sadly have not found a machine that can do more then 1 plate at a time.

More realistic option: Grow up a small culture of your cells. From that culture, dilute the cells at a known ratio.

Set up several fresh cultures. Use a define amount of dilute cultures to innoculate the new medium. Start your OD readings (record the time since starting of innoculation).

Now just before you leave set up several more fresh cultures. As before, use the same amount of diluted culture, to innoculate the new medium (of a set volume). Throw cultures into incubator (or whatever temperature you grow your cells at). Set a timer. Go home.

The next day, you can resume your OD reading. Since you have a timer(s) you know percisely how much time has elapse since starting the first and second group of cultures. The first group of cultures will now have grown for at least 24 hrs and the second at least 12hrs. Collect the data from both lots of cultures.

Since you are using the exact same strain with the same innoculation size and the same culture volume, and you are collecting readings from several repeated cultures, you should get values that are comparable to each other.

Thanks Pernesblue. It worked like a charm.