Antigene oligodeoxynucleotide

[Kappei KOBAYASHI]

Dear netters, 
        I'm considering the design of antigene oligodeoxynucleotide (ODN) 
to control stress gene expression.  I intend to synthesize 13-mer ODN 
consisted of thymine and 5-methyl-cytosin and 5'-linked acrydine, 
which is expected to form triplex on stress 70 promoter. 

        I hope someone to tell me whether or not
1)phosphorothioate modification of the ODN is needed?
2)a single mismatch at 3' terminus reduce the stability of expected
triplex?
3)there are some other strategies (or modification) of ODN to improve it 
in the ability to shutt off the gene expression?

Other recent info on antigene ODN would be appreciated.

Thanks in advance

Kappei Kobayashi (kappei at basic2.kpu-m.ac.jp)