Question

1. Show your working out for the following calculation

a)

TENS buffer:                                     Make from

0.1M NaOH                                        from stock 10M

0.2% SDS                                           from 10% stock

1mM EDTA                                        from 0.5M stock

10mM Tris pH 7.5                              from 1M stock

How would you make 200ml of TENS buffer from these stock solutions?

b)   

5M LiCl

How would you make 5M LiCl (MW=42.40g/mol)?

c)

70% Ethanol

How would you make 1L of 70% Ethanol?

d)

HisTag Protein Purification Solutions

Charge Buffer

50mM NiSO4.6H2O

Binding Buffer

5.0mM Imidazole (MW=68.08g/mol)

0.5M NaCl (MW=58g/mol)

20mM Tris pH8

Wash Buffer

60mM Imidazole

0.5M NaCl

20mM Tris pH8

Elution Buffer

1.0M Imidazole

0.5M NaCl

20mM Tris pH8

How would you make 50ml of the Wash Buffer? (assume you have a solution of 1M Tris pH 8)

Answer 1

TENS Buffer contains Tris, EDTA and NaOH.

1 Litre of TENS contains

10ml of 10 mM Tris-HCl

2ml of 1 mM EDTA

So for 200 ml you will require 2ml of 1M Tris-Cl pH 8 and 0.4 ml of 1 mM EDTA to be dissolved in 197.6 ml of water.

Adjust the pH of the solution using NaOH solution