DNA synthesis has traditionally been quite wasteful of monomer due to significant dead volume in the synthesis columns. This problem has now been alleviated by the introduction of low volume columns for Applied Biosystems' instruments. For optimal flow characteristics, polystyrene is preferred as the support in these columns. We have chosen the industry-standard "SNAP" design for these columns which are available in 40 nmole and 200 nmole sizes. With reduced volumes and the optimized cycles from Applied Biosystems, these columns will lead to more cost-effective use of small packs of expensive monomers like the phosphoramidites of unusual bases, and modification and labelling reagents.
TWIST columns are now available in 10 and 15 micromole sizes suitable for Applied Biosystems and PerSeptive synthesizers, respectively. These larger columns can be opened as easily as the original small-scale TWIST columns.
TWIST is a trademark of Glen Research Corporation.