Dear Matilde,

Patrick van Oostveldt also recommended Chromomycin A3 when I had a similar
question in November (Thanks Patrick!). It works quite well when excited
with 488nm. A problem for me was (and might be one for you) that it has a
broad emission spectrum: It is clearly visible in the usual FITC and TRITC
filters. However it does stain only DNA and not RNA (in my experiments at
least). Thus it seems to be the only non-blue DNA-specific dye on the
market (with the exception of mithramycin which is structually similar). It
would be happy to hear that I am wrong, btw.

For more information see e.g.
www.sigma.sial.com/sigma/proddata/c2659.htm
www.sigma.sial.com/sigma/proddata/m6891.htm
facspc.dfci.harvard.edu/dna_chrom.html


Hope this helps

Steffen


>One of my colleagues is interested in using the nucleic acid stain
>Ethidium homodimer-1
>(EthD-1) from Molecular Probes to label nuclei in plant cells. He needs an
>alternative to
>DAPI which we could use with an Argon (488/514)  or HeNe laser for
>confocal work.
>Does anybody know how EthD-1 compares to DAPI in specificity for DNA vs. RNA,
>permeability, etc?
>Does anybody have a suggestion of another dye which would have similar
>specificity than
>DAPI but could be used with an Ar/He-Ne laser system?
>We would appreciate any information that anybody could make available to
>us, before he
>decides to purchase the dye (since it is pricy).
>Thanks in advance,
>
>Matilde M. Urrutia
>Dept. Biological Sciences
>The University of Alabama
>Box 870206
>Tuscaloosa, AL, 35487-0206
>
>e-mail: [log in to unmask]

-- -------------------------------------------------------------
Dr. Steffen Dietzel
Zentrum fuer molekulare Biologie Heidelberg (ZMBH)
University of Heidelberg
Im Neuenheimer Feld 282
69120 Heidelberg, Germany
Phone: +49/6221/54-6836 or -6879. Fax: -5893
listservmail:[log in to unmask]
personal mail: [log in to unmask]