Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

2mg/ml from a 2U/ml solution?HELP!

  1. Sep 16, 2004 #1
    2mg/ml from a 2U/ml solution????HELP!

    hello guys!

    I need to prepare a 2 mg/mL DNAase solution. the DNAase stock has a concentration of 2U/ml. how can i make a 2mg/ml from a 2U/ml solution? this is quite hard to figure out :yuck:


    hope very much for replies!

    thanks for helping!
     
  2. jcsd
  3. Sep 17, 2004 #2

    Monique

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Look up the specific activity (in U/mg) of the DNase that you have, which company are you using it from? You should look in the catalog under DNase, you will find all the specifications.
     
  4. Sep 17, 2004 #3
    hi Monique!

    hope that you can help me out!
    the Qiagen explicitily says that one mg = 2500 Kunitz units. but still my brain doesn't "work" :cry:
    can you please show me how you would make a 2mg/ml from a 2U/ml if 1mg=2500 Kunitz units? by the way what does Kunitz units mean?

    hope so much for advices!
     
  5. Sep 17, 2004 #4

    iansmith

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    but it is not the same as U

    http://www.unc.edu/~rowlett/units/dictK.html

    Enzyme unit can also change from manufacturor. You may need to search the supplier website as alot of information is available in their tech. bulletin that are not available in their catalogues. For example fermatas says that 1 Kunitz unit of some of their enzyme is equal to 50 U.
     
  6. Sep 17, 2004 #5

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Don't waste your time hunting through catalogs and websites. Call the manufacturer's tech support directly and ask them. Have the catalog # and lot # on hand. Depending on the size of the company, the person answering the phone may or may not be able to answer your question, but let them do the legwork of finding the person there who knows the answer.

    However, units refers to the actual activity of the DNase, so you might be better off using it in U/ml than mg/ml to be more consistent from reaction to reaction. Iansmith or Monique, you two work with these methods more often than I do...do you have an opinion on whether it's better to work with concentrations in U/ml than mg/ml for an enzyme such as this? Of course, the first time, mountain will need to know the conversion just to get close to what has been used previously.
     
  7. Sep 17, 2004 #6

    iansmith

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    We usually use the U/uL for enzyme in solution and g/mL for freeze dry enzyme.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: 2mg/ml from a 2U/ml solution?HELP!
  1. Biuret Solution! (Replies: 2)

Loading...