Homogeneous real-time detection of single-nucleotide polymorphisms by strand displacement amplification on the BD ProbeTec ET System

Background: The. BD ProbeTec(TM) ET System is based on isothermal strand displacement amplification (SDA) of target nucleic acid coupled with homogeneous real-time detection using fluorescent probes. We have developed a novel, rapid method using this platform that incorporates a universal detection format for identification of single-nucleotide polymorphisms (SNPs) and other genotypic variations. Method: The system uses a common pair of fluorescent Detector Probes in conjunction With unlabeled allele. specific Adapter Primers and a universal buffer chemistry to permit analysis of multiple SNP loci under generic assay conditions. We used Detector Probes labeled with different dyes to facilitate differentiation of two alternative alleles in, a single reaction with no postamplification manipulation. We analyzed six SNPS within the human beta(2)-adrenergic receptor (beta(2)AR) gene, using whole blood, buccal swabs, and urine samples, and compared results with those obtained by DNA sequencing. Results: Unprocessed whole blood was successfully genotyped with as little as 0.1-1 muL of simple per reaction. All six beta(2)AR, assays were able to accommodate greater than or equal to20 muL of unprocessed whole blood. For the 14 individual tested, genotypes determined With the Six beta(2)AR assays agreed with DNA sequencing results. Conclusion: SDA-based allelic differentiation on the BD ProbeTec ET System can detect SNPs rapidly, using whole blood, buccal swabs, or urine. (C) 2003 American Association for Clinical Chemistry.