Abstract: Disclosed is an apparatus for the production of tissue from cells. The apparatus comprises an elongate body having at least one circumferential groove and being operable to extend, by close-fitting relationship, centrally through at least one trough. The troughs are extending in a closed path, such that the at least one of the circumferential grooves open into an inner edge of a trough. Also disclosed is a process for production of tissue from cells, via a transitioning intermediate which transitions from the cells into the tissue.