Ohio Valley, located in Marietta, Ohio, has been manufacturing GC columns and accessories for more than 50 years. Ohio Valley uses fused silica tubing to manufacture its capillary columns and markets its genuine OV® liquid phases all around the world. All OV® columns are bonded and cross linked. Each column is conditioned to achieve excellent thermal stability and allow a long lifetime for the column. Advanced deactivation techniques at extreme temperatures are used to make OV GC capillary the most inert possible. Each capillary column is tested individually. The deactivated tubing is ideal for use as guard columns or retention gap columns.