Question

a) Calculate how you would make 1.0 L of 10x TBE (0.9 M Tris, 0.9 M Boric Acid, 20 mM EDTA) Tris MW=121.4 g/mole; Boric Acid MW=61.84 g/mole; EDTA MW=292.2 g/mole

b) For your polyacrylamide gel electrophoresis gel you need 50 mL of 0.5x TBE. Calculate and describe how you would make this solution using your stock solution.

Answer 1

(a)

0.9 M tris .

So first step is calculate weight.

Weight of tris = molarity*molecular weight *Volume=0.9 mol/lit *121.4 g /mole *1 lit = 109.3 gm

Weight of boric acid = 0.9 mol/lit * 61.84 g/mole *1 lit = 55.6 gm

Weight of EDTA =20*10^-3 mol/lit * 292.2 gm/mole *1 lit =5.84 gm.

Dissolve 109.3 gm of tris,55.6 gm of boric acid and 5.84 gm of EDTA in 1 lit of water.

(b)

TBE diluted 10x to 0.5x

C₁V₁=C₂V₂

(10x)V₁ = 0.5x*1lit

V₁ = 0.05 lit = 50 ml

So Dilute 50 ml of TBE in 950 ml of water