Dextran Sulfate 10% vs 5%

[Eric H. Westin]

Have tried 5 vs 10% in straight (lower molecular weight, ie up to 
approx.15 kbp) and it does not appear to further inprove the signal 
provided your hybridization and probe concentrations are otherwise 
adequate. (approx. 24 hour hybridization). If you try higher and have a 
different effect with pulse-field fragments, please let me know if it 
makes a difference.martinez at puccini.CRL.umn.edu (J. Patrick Martinez) 
wrote:
>Hi,
>
>We are currently using 5% Dextran sulfate in our hybridization solution to
>enhance the signal of single copy genes probed with radioactively labeled
>DNA.   To gain maximum signal, we were considering bumping up the Dextran
>sulfate concentration to 10% for special applications such as probing
>pulsed field gel electrophoresis blots.   Has anyone compared the effect
>of using 10% vs. 5% dextran sulfate in hybridazations? 
>
>Thanks,
>
>Pat M.