Detection of Texas red-labelled double-stranded DNA by non-enzymatic peroxyoxalate chemiluminescence

We have found previously that different fluorescent dyes cannot be efficiently excited by the bis(2,4,6-trichlorophenyl)oxalate (TCPO)-H(2)O(2) reaction when they are intercalated between the DNA bases or bound to the minor groove of the double helix. Here we show that the fluorescent dye Texas red, covalently bound to the 3' ends of double-stranded DNA molecules, exhibits a high emission intensity when excited by the TCPO-H(2)O(2) reaction. In this case, the charge transfer between the intermediate produced in the peroxyoxalate chemiluminescent reaction and Texas red can take place because this fluorophore is not buried inside the DNA structure. We describe the application of this chemiluminescent reaction to the detection of blotted DNA on nylon membranes.