Archive for the ‘Computer’ Category

Calculating Doubling Times

Thursday, September 24th, 2009

Folks in the lab have recently been calculating doubling times of strains. I found doing the calculations one at a time tedious, so I put together a spreadsheet to automatically handle the data from the Biotek plate reader in batch.

I probably spent a totally unreasonable amount of time putting this together, but hopefully someone will find it useful. It is particularly optimized to work with the raw data as it is spit out into Excel by the KC4 program. It is set up to work with the scales of data that I get out (48 hour growth, final OD ~0.8), but you should be able to easily modify the settings to work better for your data.

To start, you simply copy the raw data from your Excel worksheet to the worksheet in the calculator helpfully named “Raw Data”.  There is already a data set pasted in to demonstrate some of the functions, so simply delete it before you add your own data.

There’s a lot going on in there, so if you need something and can’t find it, then track me down, because it is probably hidden somewhere. Alternatively, you can start unhiding rows and try to disentangle the works yourself…


An additional note on calculating doubling times: I would assert that they should be calculated using corrected OD values (OD values where the initial un-inoculated reading is subtracted from all subsequent readings). Anyone want to challenge this?

Good luck!

Get DoublingTimeCalculator!


-- Doug