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## Generation Time... HELP?!

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### Generation Time... HELP?!

I am new to this forum but I need help! I am currently dong a microbiology report at university. We done an experiment on two cultures (L and M) measuring the growth using a spectrophotometer set at OD600 at set time intervals (every 30mins, 0-150). We then had to find and plot the natural log, these were my results (obviously not on a graph):

Time Culture L lnCulture L Culture M lnCulture M
0 0.065 -2.733368009 0.026 -3.649658741
30 0.167 -1.789761467 0.043 -3.146555163
60 0.335 -1.093624747 0.044 -3.123565645
90 0.508 -0.677273831 0.064 -2.748872196
120 0.942 -0.059750004 0.082 -2.501036032
150 1.322 0.279145741 0.117 -2.145581344

We then had to find the cells ml^-1, which was easy enough, then had to find the specific growth rate and generation time of each culture using the following equations:

μ = (lnODt2 – lnODt1) / (t2 – t1) and g = ln2 / μ

I think I managed to get the growth rate (μL = 0.021h^-1 and μM = 0.010h^-1) but I can't seem to figure out how to get the generation time?! I have been looking at it for so long and have tried so many different things that I've completely confused myself (I ended up with 33 and 69 hours or something ridiculous)...

Sorry for rambling... ANY help would be much appreciated, I'm so annoyed and confused!

Thanks a lot.
baffledbiologist
Garter

Posts: 3
Joined: Sat Oct 15, 2011 11:51 pm

Oops! My results aren't very clear. Sorry, I'm not sure how to sort it so I hope someone can decifer them and solve my issues!
baffledbiologist
Garter

Posts: 3
Joined: Sat Oct 15, 2011 11:51 pm

Okay sorry again! I have managed it! Not sure how I delete this though, technology is not my forte.
baffledbiologist
Garter

Posts: 3
Joined: Sat Oct 15, 2011 11:51 pm

Sounds like from reading this that you missed a decimal because your work is right. I got a time of 33 minutes and 69 minutes which is reasonable.
daniel.kurz
Coral

Posts: 167
Joined: Fri May 19, 2006 1:47 am