NUCLEIC-ACIDS HYBRIDIZATION SYSTEM WITH DNA PROBES DIRECTLY LABELED WITH PEROXIDASE

A system for non-radioactive detection of nucleic acids hybridization was developed by use of DNA probes directly labeled with peroxidase. The aliphatic hydrazide groups were bound to DNA at C4 position of cytidine 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: composition of hybridization mixture, mass ratio of peroxidase to DNA in probe synthesis and probe concentration during hybridization. Sensitivity 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.