Question

You have just begun working in a research laboratory. Your advisor asks you to make a series of stock solutions. He also explains that you may use a pH meter to adjust the pH. Calculate how much of the solid reagent you would add to make the following:

500 mL 1 M Tris, pH 8.0 (MW = 121.4 g/mole)

1.0 L 5 M NaCl (MW = 58.44 g/mole)

10 mL 100 mg/mL Ampicillin (MW = 371.4 g/mole)

500 mL 0.5 M EDTA (Ethylene Diamine Tetra-acetic Acid; MW = 292.2 g/mol)

200 mL 1 M MgCl2 (Note: MgCl2 is sold by the chemical company as co- crystallized with H20. Thus, the MW of MgCl2 6H20 is 203.30 g/mole)

For your first experiment, you need to make a solution that is commonly called TE and stands for Tris-EDTA. It is comprised of 10 mM Tris, 1 mM EDTA, pH 8.0. Calculate and describe how you would make 100 ml of TE using the stock solutions that you have already made above in Question 1.

Your advisor asks you to make two concentrated stock solutions for the whole laboratory to use. He explains that it is common to make a concentrated solution to dilute for use. Thus, a 10x solution refers to one that is 10-fold concentrated. Calculate how you would make 1.0 L of each of the following:

A. 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. 50x TAE (2 M Tris, 2 M Acetic acid, 0.5 M EDTA) Tris MW = 121.4 g/mole

Concentrated Acetic acid (glacial) comes as a solution and is 17.4 M EDTA MW = 292.2 g/mole

Your polyacrylamide gel electrophoresis experiment requires 1.0 L of 0.5x TBE. Calculate and describe how you would make this solution using your stock solutions