Coupling columns of same or different resin materials is often employed in complex proteomic digest analysis. Despite enhanced separation, these multidimensional columns are costly, timeconsuming to produce, and initiate post-column loss by deadvolume introduction. Confounding factors of column-coupling can be eliminated via transparent, true zero-dead-volume (ZDV) unions that achieve flush connections and rapid swap-out facility during system maintenance. In the current investigation, two conventional 10 cm-bedded columns were coupled and connected to the bed terminus of a third 10 cm nanobore column with integrally fritted tip. Analytical merit of this extended column was compared with a single 30 cm-bedded column with integrally fritted tip and the same resin material. These novel unions supported chromatographic data collection with zero dead-volume, negligible resolution loss, and comparable caliber as the single 30 cm-bedded column.