A kit for injecting a biomaterial into an intradiscal space accessed through an opening in the disc annulus comprises a plurality of needles, each sized for introduction through the annulus opening with a passageway for injecting the biomaterial therethrough, and each including a distal end to be disposed within the intradiscal space when the needle extends through the annulus opening. Each needle includes a stop affixed thereto at different pre-determined distances from the distal end to define the location of the distal end within the intradiscal space when the needle extends through the opening in the annulus. The kit further includes a plurality of seals defining a bore for sliding engagement with a needle, each of the plurality of seals including a sealing face for engaging the annulus around the needle. Each sealing face defines a differently configured area of contact, such as circular, elliptical, tapered and threaded.