A number of various DNA CPG column formats are available, compatible with a range of instruments. “Hybrid” columns have pipette tips that fit both MerMade™ and other pipette-based synthesizers, such as the ABI 3900. They have medium porosity Porex frits, and leave headspace above the CPG. Typically, our Prime Synthesis CPG is packed in Hybrid columns. “Supercolumns™” have an upper pipette fitting and a lower luer fitting, suitable for MerMade™ and other pipette-based synthesizers such as ABI 3900 and Dr Oligo. They differ only from Hybrid columns in that they are frit stomped to remove headspace over the CPG. “Standard” or “ALL-FIT” columns are for use on DNA synthesizers that use luer-to-luer fittings. Examples are the ABI 394 and Expedite 8900/8909. TWIST™ columns are also designed for use on synthesizers with luer fittings. TWIST™ columns have a screw cap and are useful if the column has to be opened to manipulate the synthesis support and then resealed. TWIST™ is a trademark of Glen Research Corporation.