Subject: CCL:Fluorescence from Intercalated Dye

From: "Telkuni Tsuru" <telkuni..at..venus.dti.ne.jp>
Date: Thu, 22 Jul 2004 14:53:48 +0900

Hello, CCLers.

I like to ask my interpretation for the fluorescence from the intercalated dye.
All responses, I will appreciate and summarize them.

I'm studying the fluorescence intensity magnification of the intercalated dye
> from the viewpoint of molecular orbital theory. My question is about the
mechanism of this magnification, and I need your comment for my 
interpretation.

  For example, when a dye EtBr(Ethidium Bromide) intercalated into the
  stacked DNA(*) or RNA bases (it is just like a sandwich !), the fluorescence
  intensity is magnified.
  (*) Bases are paired and stacked 

I've read books, papers, and web documents, but I'm yet to understand the
correct theoretical and molecular orbital effect from stacked bases.

Now, I guess the scheme between the stacked bases and dye as follows:
  The dye had intercalated.
  --> MOs of dye are changed by each base.
  --> Degree-of-freedom of dye electron is increased, so the charge separation
      become easier.
  --> Quantum yield for fluorescence is increased, then the fluorescence 
      intensity is magnified.

  ... Is this scheme true? Comment please.

  Thanks in advance,

--------------------------------------------------------
          Telkuni Tsuru        telkuni..at..venus.dti.ne.jp
                        Tekcel corp.
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