Capture and release of DNA using aminosilane‐modified bacterial magnetic particles for automated detection system of single nucleotide polymorphisms

Bacterial magnetic particles (BMPs) were modified with 3‐[2‐(2‐aminoethylamino)‐ethylamino]‐propyltrimethoxysilane (AEEA) to produce a dense amine surface. Modification of BMPs in a toluene solution resulted in an increased amine yield, and approximately 11.3 × 10 4 surface amines were detected on a single particle. The modified BMPs were capable of efficient electrostatic capture of DNA. The maximum amount of DNA captured on 10 µg of aminosilane‐modified BMPs was 600 ng. A 10 mM phosphate buffer effectively released the captured DNA. This efficiency was dramatically enhanced by incubation at 80°C and DNA recovery from aminosilane‐modified BMPs approached 95%. DNA extraction from whole blood using these modified BMPs, followed by PCR, was successfully performed. Furthermore, automated single nucleotide polymorphism (SNP) detection of the aldehyde dehydrogenase 2 (ALDH2) was demonstrated. © 2006 Wiley Periodicals, Inc.