maxXbond: first regeneration system for DNA binding silica matrices

ADVERTISING FEATURE © 2006 Nature Publishing Group http://www.nature.com/naturemethods APPLICATION NOTES maxXbond: first regeneration system for DNA binding silica matrices New solutions allow multiple reuse of valuable material. Silica matrices are a key technology for the purification of DNA. Today the rapid isolation of pure DNA samples is essential for a a H L variety of molecular biology protocols in research and commercial applications. Products with silica matrices are of high quality and high value. Their major disadvantage is that they can only be used once because after elution substantial amounts of DNA remain attached to the silica matrix and the binding capacity is reduced. To solve this problem AppliChem GmbH, Darmstadt in cooperation with multiBIND GmbH, Dortmund developed the first regeneration Binding b Elution F system for silica matrices. Two innovative solutions remove all nucleic acids and extraneous material from silica matrices and restore the original binding capacity. The regeneration system is commercially I available under the name maxXbond. This new product family optimized for the unique regeneration technology allows cost savings 5–10% of about 70%. I 90–95% Regeneration technology for silica matrices The unique properties of silica matrices for selective DNA binding (Fig. 1a) are the basis for all products related to fast and efficient DNA purification. For more than two decades, more efficient and application-oriented systems for DNA and RNA have been developed1,2. Glass powder (‘glass milk’; ‘batch procedure’) or silica columns allow quick and efficient purification procedures3. Principles and problems Figure 1 | Binding of DNA to silica matrix and mini columns. (a) The purification principle for silica matrices is based on the high affinity of the negatively charged DNA molecule for the positively charged silica particles (blue). Under high salt conditions the DNA is tightly bound and extensive washing removes all contaminations, and purified DNA molecules can be eluted under low ionic strength. (b) With mini-columns, elution removes only 90–95% of the DNA. The column remains contaminated with DNA molecules and/or inclusions in protein particles or bacterial fragments, and thus has reduced DNA binding capacity. associated with silica matrices are summarized for mini columns (Fig. 1b). Two major tasks for a successful regeneration system are complete removal of residual DNA and restoration of primary bind- The two-component maxXbond system with regeneration buf- ing capacity. Therefore, for a regeneration technology to be useful, the fer 1 (RG1) and 2 (RG2) fulfills these requirements. Rapid, efficient following prerequisites have to be met: regeneration of DNA binding columns takes only 6 min (Fig. 2). • quick and easy handling Quantitative analysis of DNA yields demonstrates that the binding • complete removal of all nucleic acids (both free and trapped) capacity of regenerated columns is the same as for new columns (Fig. • no damage to the silica matrix 3a). Analytical agarose gels2 and PCR analysis4 verify that regenerated • complete regeneration of the DNA binding capacity columns are nucleic acid-free (Fig. 3b,c). Additional experimental • affordability. controls for the quality and purity of DNA from regenerated columns are documented in the detailed product information (http://www. Karl-Heinz Esser1, Wolfram H Marx2 & Thomas Lisowsky1 1multiBIND biotec GmbH, Otto Hahn Str. 15, D-44227, Dortmund, Germany. 2AppliChem applichem.com). A single DNA binding column can be reused at least 20 times5. Additional considerations in the development and success of the GmbH, Ottoweg 4, D-64291 Darmstadt, Germany. Correspondence should be addressed to T.L. () or W.H.M. (). new maxXbond regeneration system are the innovative characteristics PUBLISHED ONLINE 20 DECEMBER 2005; DOI:10.1038/NMETH845 of the new solutions: NATURE METHODS | JANUARY 2006 | i ADVERTISING FEATURE APPLICATION NOTES 5-10% of DNA a b Column: A A A A B B B B Plasmid: X X X X Y Y Y Y Usage: 1× 5× 10× 20× 1× 5× 10× 20× Column: C D C D Plasmid: X X Y Y Usage: 1× 1× 2× 2× c Plasmid X Plasmid X 750 750 Primer © 2006 Nature Publishing Group http://www.nature.com/naturemethods Primer I No incubation C C Figure 3 | Quality control of maxXbond-regenerated columns. (a) Restored binding capacity after 20 regeneration cycles. Columns A or B were used and regenerated for 20 cycles of plasmid DNA isolation. Regenerated columns are nucleic acid-free. (b,c) Columns C and D were used for the isolation of plasmid X. After regeneration, plasmid Y was purified with the identical columns; the second DNA isolation of sample Y does not contain any traces of the first DNA sample X (b). PCR analysis does not reveal any DNA molecules from the first isolation (c). Before purification of DNA sample Y, columns C and D were treated with RG1 for 24 h and 5 min, respectively. Then, 750 µl RG2 were applied to each column. Finally, DNA was eluted in 50 µl of elution buffer. Then, 2 µl of eluates were subjected to PCR with appropriate primers for insert in X. C1, control with 1 ng plasmid X DNA; 0, no DNA; C2, control with 1 ng plasmid X DNA and 2 µl of each eluate after the regeneration of columns C and D. Figure 2 | Scheme for the new maxXbond regeneration procedure for DNA binding columns. Regeneration solutions are applied successively to the column. • All components of maxXbond are bio-degradable, harmless or non-toxic for humans. • No aggressive acids or bases are used. No damage to material or equipment is observed even after prolonged incubation. • Catalytic and cooperative properties of the maxXbond components • All solutions can be stored at room temperature. cause a rapid and efficient removal or degradation of biological New tests demonstrate that maxXbond also regenerates free silica molecules like membrane fragments, proteins and nucleic acids. particles for DNA fragment purification and columns with silica matrix • Solutions remain active even in the pH range from 6 to 8. for the purification of PCR products. The latest member of the product The new maxXbond regeneration system can be applied to all com- family is maxXmore PCR, a buffer set with two optimized solutions for mercially available DNA binding columns that contain silica matrices. the purification of PCR products with regenerated columns. Preliminary data indicate that any other DNA binding material like glass powder or minerals can also be regenerated by maxXbond. The Conclusions new product maxXbond is now available to both academic and indus- The first regeneration system for silica matrices allows substantial cost trial scientists who seek to optimize their DNA isolation procedures savings. The high interest of the scientific community and the positive and save a substantial part of their respective costs. The maxXbond feedback of the primary users ha (...truncated)