[Histonet] Qdots - fading now ... not as described on spec sheets

[GT Hebert]

Hello all,
   
  I have been using secondary antibodies conjugated to Qdots for more than a year now.  With high success in staining, I had started switching my immunofluorescence protocols from Alexa conjugated secondaries to Qdot conjugated secondaries.
   
  Up until recently everything worked well ... and all my slides (4%PF or 10%NBF animal tissue, processed routinely - paraffin embedded) were remaining fluorescent.
   
  A few months passed by (as worked and studies shifted to other priorities) and this past February I picked up using Qdots again.  With all new reagents (Qdot secondaries, buffer, etc), but the same protocol - I ran my immunos.  However, in every case, my fluorescence was complete quenched (gone) the following day.
   
  Is anyone who also uses Qdots experiencing this lately?
   
  I have spoken with Invitrogen (Molecular Probes) and they have described this as a fairly recent problem and their R&D group is looking into it.  However, their marketing team continues to push Qdots as brighter and longer lasting than conventional organic dyes and Alexa dyes.  
   
  Any information would be appreciated.
   
  Thank you.
   
  Gustave Hebert 
  Scientist II
  Wyeth Research 
  Cambridge, MA

       
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