Science Buddies: "Ask an Expert"

Hi
We are trying to verify the low concentration for this experiment. The calculations for the high concentration make sense but is it correct that the low concentration for antifungal medications of 1% would be 10,000- fold dilution which is 5ug/mL concentration of antifungal agent? Thanks!

The calculations are a little tricky but as I read them: https://www.sciencebuddies.org/science- ... #procedure

The LOW concentration of antifungal medication is prepared by diluting 1/8 tsp of the HIGH, 1000-fold solution (10 ug/ml), into 1/4 cup of water (12 tsp or 96 eighth tsp) which is a 100-fold dilution. So, a 100-fold dilution of a 1000-fold dilution is a 100,000-fold dilution if my reasoning is correct.

Other experts please CHECK!!

The high concentration (given that the antifungal chemical is at 1%) is 10 ug/ml, so the low concentration would be 1/100 of that or 0.10 ug/ml.

Does that sound correct to you?

Sybee

Hi Sybee
Thanks so much for your response! Your reasoning and calculations make sense to us now that we see the logic you used. Thanks very much for the help!