IC50 and CC50

IC50 is the minimum inhibition concentration for inhibiting 50% of the pathogen and CC50 is the Cytotoxic concentration of the compound to cause death to 50% of viable cells in the host. These are measured through dilution assays of the selected compound and they are added to virus infected host cells.

The Ideal situation is to have the IC50 concentration below the CC50 concentration and your CC50 as high as possible.

This mean that you kill the pathogen before killing the host. These are important factors to consider when developing anti microbial compounds.

SI = CC50/IC50 

SI is a index value that gives you an idea about the selectivity. You need this to be a high value number which means that you achieve killing the virus before your host, i.e. the compound has selectivity towards your virus and not your host.

Why do we have to measure IC50, CC50 and SI?. Available from: https://www.researchgate.net/post/Why_do_we_have_to_measure_IC50_CC50_and_SI