Five new enzyme-triggered dioxetane substrates were evaluated for rest
riction fragment length polymorphism (RFLP) analysis of HaeIII-restric
ted DNA. Of these, one substrate designated CDP-Star provided unsurpas
sed sensitivity within one working day without the presence of an enha
ncer. Far greater sensitivity was obtained from chemiluminescent detec
tion of DNA on MSI neutral membranes than the sensitivity obtained fro
m six day film exposures of P-32 labelled insert probes on PALL B memb
ranes, including the detection of most low molecular weight alleles. F
or nylon membranes better suited for alkaline phosphatase-triggered ch
emiluminescent detection of DNA, high salt/neutral pH southern transfe
r conditions were better than alkaline southern transfer conditions.