MOLECULAR BIOTECHNOLOGY Volume 27, 2004 Magnetic Fishing of DNA and RNA 209 RESEARCH PROTOCOL 209 Molecular Biotechnology © 2004 Humana Press Inc. All rights of any nature whatsoever reserved. 1073–6085/2004/27:3/209–215/$25.00 Abstract *Author to whom all correspondence and reprint requests should be addressed: 1 Department of Biology, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland.E-mail: jaana.vuosku@oulu.fi; 2 Parkano Research Center, Finnish Forest Research Institute, Finland. Does Extraction of DNA and RNA by Magnetic Fishing Work for Diverse Plant Species? Jaana Vuosku,* ,1 Laura Jaakola, 1 Soile Jokipii, 1 Katja Karppinen, 1 Terttu Kämäräinen, 1 Veli-Pekka Pelkonen, 1 Anne Jokela, 1 Tytti Sarjala, 2 Anja Hohtola, 1 and Hely Häggman 1 An automated nucleic acid extraction procedure with magnetic particles originally designed for isolation of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) from animal tissues was tested for plant mate- rial. We isolated genomic DNA and total RNA from taxonomically diverse plant species representing coni- fers (Scots pine), broad-leaved trees (silver birch and hybrid aspen), dwarf shrubs (bilberry), and both monocotyledonous (regal lily) and dicotyledonous (Saint John’s wort, round-leaved sundew, and tobacco) herbaceous plants. Buffers developed for DNA extraction were successfully used in addition to manufacturer’s extraction kits. The quality of RNA was appropriate for many applications, but the quality of DNA was not always sufficient for polymerase chain reaction (PCR) amplification. However, we could strikingly improve the quality by eliminating the adherent compounds during the extraction or later in the PCR phase. Our results show that the use of the procedure could be extended to diverse plant species. This procedure is especially suitable for small sample sizes and for simultaneous processing of many samples enabling large-scale plant applications in population genetics, or in the screening of putative transgenic plants. Index Entries: DNA isolation; RNA isolation; magnetic separation; PCR amplification; digestion. 1. Introduction The extraction of intact high-quality deoxyri- bonucleic acid (DNA) or ribonucleic acid (RNA) is a critical step in many molecular biology tech- niques. Isolation of high-quality nucleic acids is known to be difficult from several plant species either because of the presence of polysaccharides, which are difficult to separate from nucleic acids (1,2), or owing to the remarkable variety and fre- quently large quantities of secondary metabolites, which may inhibit DNA polymerases and restric- tion enzymes. It is well known that cell lysis re- leases polysaccharides and phenolic compounds, which may irreversibly adhere to nucleic acids (3–8). In addition, the yield of RNA may be af- fected by ribonucleases found at elevated levels in many plant tissues (9). The classical methods of DNA and RNA isola- tion are either column-based techniques or include precipitation and centrifugation steps. They have the disadvantage of being time-consuming, diffi- cult to automate, or not usable for small-scale work. When magnetic particles are used, these major limitations can be avoided. Extraction and purification of nucleic acids based on magnetic beads have been used and tested for years (10–12). As far as plants are concerned, magnetic beads have been used for the isolation of messenger RNA from individual plant cells (13) and for the extraction of DNA from small amounts of plant tissue (14). However, the use of magnetic beads in DNA or RNA isolations from plants has not been widespread partly owing to the lack of an efficient automation system to operate magnetic particles.