BIOL 3810 Name: ____________________________________Solution Problem Set TA Name:___________________________________________

Write answers clearly and please box or otherwise indicate final answers. You must show all work!

You are given the following solutions and solids:

Solids: Tris (FW = 121 g/mol) SDS (FW = 288 g/mol) NaCl (FW = 58 g/mol) KCl (FW = 74 g/mol)

Stock Solutions: 50% KCl 10x TBE 10% Glycerol 20% SDS

1. Write the calculations to make the following solutions using only the stocks and solids listed above. Assume all the above solutions are in deionized water. Remember that for some calculations you do not need the Formula Weight!!!! (9 pts)

a. How would you prepare a 1 L solution containing 1.5 M Tris, 0.1% SDS and 1 mg/L KCl? There is more than one solution to this problem!

b. How would you prepare a 0.75 mL solution containing 50 μM NaCl, 5% KCl, and 5x TBE? Pay attention to prefixes! Remember, μM= 10-6 M!

c. What are the concentrations of the components in the following solution: 500 mL containing 20 mL of 50% Glycerol, 6.05g Tris, and 50 g of Chemical X? There is no physical data available on Chemical X!

d. How would you prepare a 25 μL mixture of Primer A and Primer B at a concentration of 0.1% each? Assume your primer stocks are A=10% and B=25%

e. How would you prepare 100 mL of a DNA solution at 1:750 in 0.5X TBE? Assume the DNA solution is 1:10.

f. How would you prepare 100 mL of a 2% agarose solution in 0.1X TBE? This is definitely the easiest problem to solve!

BIOL 3810 Name: ____________________________________Solution Problem Set TA Name:___________________________________________

2. (1.5 pts) Write out the scientific notation used for the following prefixes

a. kilo- ________ b. milli- ________

c. micro - ________ d. nano- ________

e. centi - ________ f. mega- ________

3. Unit Conversions (2 pts.):

a. 0.050M = ________________ mM b. 0.000001M = ________________mM

c. 0.0001M = _______________ μM d. 300 mM = ___________________ M

e. 3 μM = __________________ M f. 0.35 mM = __________________ μM

g. 62 μM = _________________mM g. 10 mM = ____________________ M

4. Fill in the missing values (2 pts)

pH [H+]

6.89  

  1.3 x 10-3 M

13.27  

  9.7 x 10-5 mM

5. You need to prepare 100 mL of 1 M Tris buffer with a final pH of 6.8. (3.5 pts)

F.W Tris Base – 121.14 g/mol - Tris base in solution has a pH of 11.2

Describe all the steps you would go through in order to prepare the solution

BIOL 3810 Name: ____________________________________Solution Problem Set TA Name:___________________________________________

http://www.ncbi.nlm.nih.gov/books/NBK22410/