Laboratory Calculations Problem Set #1

Still having problems with laboratory calculations? You're not alone. These calculations are one of the main trouble spots students have in MMG 65, 101 and 102. But these problems are really not as hard as they seem. Here are some sample problems for you to practice.

1. You need to make a 1:5 dilution of a solution. You need 10 ml of the diluted solution. How much initial sample and diluent should you use?
   
   
   
2. How would you prepare 500 ml of a 10% NaCl solution?
   
   
   
3. If you have DNA with a concentration of 2 µg/µl, how much DNA (in µl) must be added to make a 20 µl solution with a DNA concentration of 1 µg/µl?
   
   
   
4. You have a 10x TBE buffer. To run a gel, you need 500 ml of a 2x solution of TBE. How do you make a 500 ml solution of 2x TBE buffer from the 10x buffer?
   
   
   
5. You want to make a 0.5% agarose gel. How much agarose (in grams) do you need to make up a 50 ml gel solution?
   
   
   
6. What is the DNA concentration of a 50 µl solution which contains 10 µl of DNA at a concentration of 4 µg/µl?
   
   
   
7. How would you make a 3x TBE buffer from a 12x TBE buffer for a total volume of 200 ml?
   Answers
   

Thanks are given to Tim Allen and the MMG graduate students for providing these problems.