A system for non-radioactive detection of nucleic acids hybridization
was developed by use of DNA probes directly labeled with peroxidase. T
he aliphatic hydrazide groups were bound to DNA at C4 position of cyti
dine residues by transamination with adipic dihydrazide. In the second
reaction the modified DNA was coupled with NaIO4 oxidized peroxidase.
The optimal conditions for hybridization reaction were examined: comp
osition of hybridization mixture, mass ratio of peroxidase to DNA in p
robe synthesis and probe concentration during hybridization. Sensitivi
ty of the probe with colorimetric detection was 50 pg. The advantages
of the detection system are its low price, high speed of hybridization
and probe stability for 6 months.