Preferential hybridization: amplification of hybridization signals with nested probes

This paper describes a protocol for the amplification of hybridization signals using single-stranded, digoxigenin-labeled probes of increasing length. Probes of different lengths were produced by a unidirectional polymerase chain reaction. Labeled probes were purified and collectively applied for the detection of immobilized nucleic acids. The method provides for a higher signal intensity than that observed with probes that cover the entire length of the target sequence. An increase of up to 4-fold in the intensity of the detection signal was observed.