A door assembly for an instrument cabinet includes a door element having a first side edge and a second side edge opposite the first side edge adapted for installation in a predetermined orientation, at least two first withdrawable pins in a region of the first side edge and at least two second pins which form a pivot axis in a region of the second side edge, wherein, in an extended condition, the first pins are in communication with a first depression in the instrument cabinet to prevent the door element pivoting about the pivot axis and, in a withdrawn condition, extend out of the first depression to permit the door element to pivot about the pivot axis, at least one handle element having a fixed part that secures to a front side of the door element and a movable part that mechanically couples to the two first pins, wherein actuation of the movable part allows the first pins which are coupled thereto, to move into a retracted condition, wherein the door element and/or the handle element are of symmetrical construction such that releasing the handle element, turning it through 180 degrees and securing the turned handle element enables functional elements to close the door assembly to be switched from the first side edge to the second side edge and vice versa.