A single nucleotide polymorphism (SNP) within the transforming growth factor-beta1 (TGF-beta1) gene was detected by hybridization-based method using bacterial magnetic particles (BMPs). TGF-beta1 is commonly associated with a single base change resulting in a Leu(10)-->Pro (T(869)-->C) polymorphism and is a genetic marker for susceptibility to osteoporosis. Short (9 bases) and specific probes were designed to detect SNP in TGF-beta1. Detection probes were immobilized on BMPs using cross-linking reagents. TGF-beta1 PCR products (139 bp) were labeled with the fluorescent dye coumarin and hybridized with detection probes on BMPs. Complementary hybridized targets gave over four times higher fluorescent intensities, compared with one base mismatched hybridizations. The SNP genotype was successfully discriminated using this technique.