How do you clean out a camelbak tube?

Help with a serial dilution problem with different amounts of solutions to each test tube...how to solve?

• 6 test tubes: A-F each of the test tubes have 1.5 mL of tap water in them. ...and there are four different solutions, basically different food coloring in each of the 4 different test tubes that get added to the 6 test tubes of water according to the steps below (red, blue, yellow, green) tube A: add 100 microL of solution 1 (red liquid food coloring) tube B: add 100 microL of the solution in tube A tube C: add 40 microL of solution 1 (red) and 40 microL of solution 2 (blue) tube D: add 30 microL of solution 4 (green) and 10 microL of solution 2 (blue) tube E: add 40 microL of solution 3 (yellow) and 40 microL of solution 4 (green) tube F: add 30 microL of solution 3 (yellow) and 20 microL of solution 1 (red) here are the questions that get answered...and where I get lost. What is the dilution in Tube A? Tube B? What is the ratio in Tube C? Tube D? Tube E? Tube F? How dilute is solution 3 in tube F? (in other words, what is the dilution for solution 3 in tube F) ...here are the answers I came up with on the q's above I tried to answer. first q: Dilution in Tube A...1/15. Tube B...1/30 (i looked at this tube as adding a 1:2 dilution) the other questions I'm stumped on If anyone could explain the answers I would really appreciate it.

• Answer:

  Tube A should be 1/16. It's the volume of red coloring (100 ul) divided by the total volume (1500 + 100 ul = 1600) Tube B is a 1/16 dilution of tube A, which makes it a 1/256 dilution of the red coloring. I think the ratio questions are just asking for the ratio of red to blue, etc. This is just the ratio of how much of each was added (30 ul green and 10 ul blue is a 3:1 ratio) The last question is the same as the first. The dilution for yellow coloring in tube F is the volume of yellow coloring divided by the total volume of water and colorings.