DILUTION PROBLEMS:

  1. You made a 1:2 dilution of serum. Then you added 2 mL of that to 4 mL of water. Then 1 mL of that was diluted to 8 mL. What was the final dilution of serum?
  2. You took 4 mL of a glucose solution and diluted it to 10 mL. Then a 1:10 dilution was made of that. What was the final dilution?
  3. In performing a serological procedure, you add 1 mL of serum to 5 mL of saline. A 1:2 serial dilution is then made. What is the dilution of serum contained in tube 6?
  4. Six tubes are placed in a rack. To all six tubes you add 2 mL of water. Then 1 mL of serum is added to the first tube and mixed well. You then transfer 1 mL of that to the second tube and again mix well. You continue the transfer of 1 mL of mixture from one tube to each subsequent tube, finally discarding 1 mL from tube 6. What is the dilution of serum contained in tube 6?
  5. How would you set up a series of tubes with a 1:4 dilution such that you end up with 3 mL of solution in each tube at the end of the procedure?
  6. How would you set up a series of tubes for a 1:2 dilution so that you end up with 0.5 mL of solution in each tube at the end of the procedure?
  7. What is the final concentration of your solution when you took 1 mL of a 100 mg/dL solution and added 9 mL of water?
  8. You had a 1,000 mg/dL solution of glucose. You took 1 mL of that and diluted it to 5 mL. Then you took 4 mL of that and added it to 12 mL of water. What is the final concentration of your glucose solution?
  9. How would you make 50 mg/dL working glucose solution from a 2.0 g/dL stock glucose solution?
  10. How would you make a 4 mg/dL uric acid working standard from a 200 mg/dL stock uric acid standard?
  11. You have a serum with 7 g/dL of protein. What is the concentration in mg/dL of protein in the 6th tube of a 1:2 serial dilution of the serum?
  12. 5 mL of a stock urea nitrogen standard contains 1mg Nitrogen. 5 mL is diluted to 10 mLs. 1 mL of this is rediluted to 10mL. 2.5 mL of this is rediluted to 25 mL. What is the concentration of nitrogen per mL of the final dilution.
  13. If you use 5 mL of stock glucose containing 10 mg/mL and dilute to 100 mL, what is the concentration of glucose per mL in the dilution?
  14. How would you dilute a 1 mg/mL urea stock standard to be equivalent to a 5 mg/dL working standard?
  15. How would you dilute a 2 mg/mL glucose stock standard to make 100 mL of a 50 mg/dL standard?

DILUTION ANSWERS:

  1. 1/48
  2. 1/25
  3. 1/192
  4. 1/729
  5. solvent volume = 3.0 mL, solute volume = 1.0 mL, mix and transfer 1.0 mL
  6. solvent volume = 0.5 mL, solute volume = 0.5 mL, mix and transfer 0.5 mL
  7. 10 mg/dL(Do you have any idea what you are doing?)yes
  8. 50 mg/dL glucose
  9. make a 1/40 dilution
  10. make a 1/50 dilution
  11. 109.4 mg/dL protein
  12. 0.001 mg/mL nitrogen
  13. 0.5 mg/mL glucose
  14. make a 1/20 dilution
  15. take 25 mL of stock and dilute to 100 mL