reusing agarose gels

[Diana Sammataro]

     Hello fellow RAPDs people.

     I am working with honey bees, spiroplasma and mites and have found
     a good protocol (when the RAPDs god/goddess are cooperating) to
     extract the DNA using Longmire's bird blood protocol and dialysis
     plus salt precipt.

     Recently, some of my primers seem to be failing since I have just
     purchases new reaction mixes, made my own MgCl and use tissue cultured
     water. I also UV pipettors, tips, and tubes as well as the water
     to get rid of negative control bands.

     A few questions:

     1.Can I reuse agarose gels, and what happens to DNA and EB in the
     gels.

     2. What is a positive control?

     As my system is shutting down in  a few minutes I will sign off
     for now.

     Please reply
     Diana Sammataro, Dept Entom.   dsammata at magnus.acs.ohio-state.edu