Described herein is an assembly and alignment tool for aligning leaflets of a soft leaflet prosthetic heart valve and fix the leaflets to each other and/or to a wireform or stent. In embodiments, the assembly or alignment tool includes a mandrel configured to support one or more leaflets of a prosthetic valve. The mandrel includes at least one suture hole disposed on the surface thereof to allow a needle to pass through when sewing the one or more leaflets to a wireform. FIGURE 2
