Thread: method to assay an antibiotic

where can i find a method to assay an antibiotic and/or an antiseptic?
does anybody know one?

What do you mean by assay? Do you mean determine what the antibiotic is, then you could use spectroscopy (although I'm not sure why this situation would come up).

If you mean determining the effectiveness of the antibiotic. This is done by placing a disc of the antibiotic and others on a plate that has been inoculated in such a way as to produce a lawn instead of isolated colonies. Then you come back 2-3 days later and measure the zone of clearing around the antibiotics. You would then usually classify the effectiveness based on its relative effectiveness compared to known antibiotics.

I suppose if you wanted to know how effective an antiseptic was you would take a swab from a surface before use of the antiseptic and then after, and calculate the number of colonies you get.

Edit: If you want to get into how the antibiotic is effective, that requires more complicated molecular biology techniques and creating a bunch of mutants and yatayata, long story short it takes lots of money and time.