Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: Dennis Slone on 21/07/2009 22:30:03

Title: Why are dyes ozone-sensitive?
Post by: Dennis Slone on 21/07/2009 22:30:03
Dennis Slone  asked the Naked Scientists:
   
Hello Chris,
 
Currently Cy5 and Cy3 dyes are used to label oligomers for analysis by microarrays. One is a red dye and the other is a green dye. Why does the red dye degrade from Ozone and not the green dye? And more important why isn't there a red dye that is stable red dye that can be used to label oligomers?
 
One of the unfortunate outcomes of this degradation of cy 5 is, there are no standards to calibrate the microarray scanners.  
 
Dennis Slone

What do you think?
Title: Why are dyes ozone-sensitive?
Post by: chris on 12/10/2009 18:21:58
Ozone is a very reactive molecule that readily grabs electrons from other species. Dye molecules are usually large and have complex structures involving delocalised electron configurations (which are responsible for the colour of the dye).

I'd therefore speculate that ozone bleaches dyes because it reacts with them, destroying the electron arrangement responsible for giving the dye its colour.

What does everyone else think?

Chris