HELP with Minimum Inhibitory Concentration (MIC) calculations

Nathaniel Sopelario nate at netspace.net.au
Wed Mar 27 06:07:58 EST 1996

Mark Fuller wrote:
> I have just conducted some experiments to determine the minimum
> inhibitory concentration (MIC) of a chemical and a bunch of different
> bacteria.  I have data covering the initial compound concentrations, the
> optical density (OD) over time of the cultures and the final compound
> and metabolite concentrations.
> 1) What should be graphed versus what?  Initial concentration vs. OD
> gives a good trend, but is there any model/equation I can use to figure
> out the MIC?  I can eyeball it, but I'd much rather do it
> mathematically.
> 2) What's the general feeling of reporting LC-50, EC-50 along with MIC
> values?
> Any input or hints on specific references would be much appreciated.
> -Mark Fuller, Ph.D.

   In Excel 5, there's a tool to have a mathematical representation of 
the graph created by the variables chosen. You can play around with it 
to determine an equation. 

Nathaniel Sopelario

More information about the Microbio mailing list

Send comments to us at biosci-help [At] net.bio.net