The present invention concerns a returnable case comprising a bottom member 1, left and right side members 2L, 2R and front and back side members 3F, 3B, wherein the front and back side members 3F, 3B are formed foldable inward in a two fold state to the bottom member 1 and, in addition, formed to be detachable. Protection of the 3-end of an oligonucleotide prevents non-specific chain elongation. The tool moves the first tape library and the second tape library into a closed, non maintenance position. The first set of pads preferably include a reset pad, a clock pad and an inputoutput pad in accordance with the ISO 7816 protocol, and may also include a variable supply voltage pad in accordance with the ISO 7816 protocol. The package holds a plurality of medical tubes in a condition in which the medical tubes are individually connected to a branching member.