A new electrophoresis technology for hybridization-based sequence detection and mutation typing is described Intrinsic to this approach is copolymerization of specially modified oligonucleotide probes directly into polyacrylamide gels. Electrophoresis of single-stranded samples through gels containing specific immobilized probes results in hybridization-mediated capture of complementary targets. By increasing gel temperature or including denaturants in the buffer the method can be used to type single-nucleotide polymorphisms. The method can easily be adapted to type mutations in PCR-amplified samples. Acrydite(TM) gel technology will also be useful for many other applications, including hybridization-based diagnostics, analysis of gene expression and purification of nucleic acids from biological samples.