Question

Prepare 100ml of homogenization buffer. Calculate how to do this with (c1V1=c2V2) where C is concentration and V is volume.

Initial Stock solutions:---------------------- Final Buffer:

50mM TrisCl, pH8.6 ---------------------------10mM TrisCl, pH 8.6

100mM PMSF-----------------------------------1mM PMSF

20mM EDTA--------------------------------------1mM EDTA

20 uM pepstatin A -------------------------------0.2 uM pepstatin A

7.1 M 2-mercaptoethanol ----------------------1 mM 2-mercaptoethanol

Please show your work so I can reason through this! Thanks

Answer 1

C₁V₁ = C₂V₂

C₁ – Concentration of Initial stock solution

V₁ – Volume of Initial stock solution to be taken for preparation of final solution

C₂ – Concentration of Final solution

V₂ – Volume of Final solution

50mM Tris Hcl

C₁ – 50mM

V₁ – ?

C₂ – 10mM

V₂ – 100ml

So V₁ = (10 x 100)/50

     V₁ = 20ml

100mM PMSF

C₁ – 100mM

V₁ – ?

C₂ – 1mM

V₂ – 100ml

So V₁ = (1 x 100)/100

     V₁ = 1ml

20mM EDTA

C₁ – 20mM

V₁ – ?

C₂ – 1mM

V₂ – 100ml

So V₁ = (1 x 100)/20

     V₁ = 5ml

20µM Pepstatin A

C₁ – 20µM

V₁ – ?

C₂ – 0.2µM

V₂ – 100ml

So V₁ = (0.2 x 100)/20

     V₁ = 1ml

7 M β-Mercaptoethanol

C₁ – 7 M

V₁ – ?

C₂ – 1mM

V₂ – 100ml

So V₁ = ((1 x 100)/7)/1000

     V₁ = 0.014ml

1000 is divided for converting Molar into Millimolar

Mix the above said volumes in a 100ml measuring cylinder or volumetric flask and make upto 100ml with the solvent that is going to dissolve