ECL very short lived signal

[Fankhauser Christian]

   Dear all,
   we encountered a sporadic problem with the signal of western blots
   revealed with ECL. Things normally work just fine (we perform a large
   amount of westerns) but every now and then even the experienced
   western blotters only get very weak or even absent signals. The
   pattern is quite systematic the signal becomes extremely short lived.
   Typically all the solutions have been replaced without much (or any
   effect), we suspected pretty much everything including our MilliQ
   water. In the end things generally work again after a few weeks
   without any obvious explanation.
   I suspect that this problem is related to the very last step when the
   enzymatic reaction should work to reveal your favorite band. Do any of
   you know if what you use to wrap the membrane after the reaction just
   before exposing it to the film makes a difference? is Saran more
   likely to work than other transparent plastics? does peroxidase care
   about something in the air (oxygen? anything else like ozone that can
   change depending on the time of the year)
   I have seen similar complains on this newsgroup on several occasions
   but I have not found a solution to this problem.
   your suggestions would be most welcome!!!
   thanks in advance   Christian Fankhauser
   
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