Below you will find the stock concentrations of the reagents

Below, you will find the stock concentrations of the reagents. Your task, is to devise a set of dilutions that will ultimately yield the correct final concentration in the bath. You can assume that you are using Tyrodes buffer to dilute the drugs. REMEMBER: the total bath volume is 20 mLs and you want to achieve the desired bath concentration by injecting 200 mu L into the bath. FYI, the smallest volume you can accurately pipette in the lab is 10 mu L and you will be using 1.5mL tubes for mixing. Eserine Stock concentration: 1 mM (or 1 times 10^-3 M) Final bath concentration required: 1 times 10^-6 M Atropine Stock concentration: 3 mM (or 3 times 10^-3 M) Final bath concentration required: 3 times 10^-7 M Write a brief description of how you will dilute the drugs so that you obtain the required final concentration. Note: there are many right answers to these dilution problems. You should aim for one that involves that least amount of work, if possible!

Solution

for eserine

M1 X V1=M2 X V2

1x10^-3 X v1= 1x10^-6 x 20

V1=20x10^-3=0.02ml

we need 0.02ml of eserine

For atropine

M1 X V1= M2 X V2

3*10^-3 X V1= 3X10^-7 X20

V1=20*10^-4=0.002ml

we need 0.002 mlof atropine