Tropix (Bedford Mass) has a kit called CDP-Star that has 8X the kinetics
of AMPPD and lasts longer than 24 hours. This works better than either
AMPPD or ECL for DNA applications. This is becuase when dealing with the
concentrations most of us use with DNA/RNA work the ECL (predominent chemi
label for protein) has too short of a half life and the AMPPD puts out to
little light. The CDP-star puts out almost as much light as ECL but keeps
going, and going like AMPPD.
I know Tropix sells it, Bio-Rad and Boehringer also sell it. I think
Bio-Rad has a phospho imager that reads chemi as well as radiation if you
are interested in quantitation.