Recent developments of magnetic beads for use in nucleic acid purification

The performance of Magarose(R), an agarose-based bead containing a paramagnetic component has been evaluated. The anion exchanger DEAE-Magarose is effective at binding DNA from a crude cell lysate. The plasmid pBluescript was isolated from 1.5 mi Escherichia coli JM109 cell culture, following alkaline lysis yielding 8.2 mu g high-quality DNA. Under similar binding conditions 21 mu g of salmon sperm DNA bound to the ion exchangers. The affinity medium oligo-dT Magarose was demonstrated to bind 75 mu mol of an oligo-dA probe/g of medium by hybridization. Under similar conditions mRNA could be isolated from a preparation of baby hamster cell total RNA. The magnetic susceptibility of Magarose is very high, facilitating the use of this separation technique for rapid batch chromatographic processes. (C) 1998 Elsevier Science B.V. All rights reserved.