Specimen pre-processing connection device and system provided with device

A specimen transport system comprising:

• a first specimen processing system that transports a specimen rack holding a specimen by a transport line;
• a second specimen processing system that is operable separately from the first specimen processing system;
• a connection unit that is disposed between the first specimen processing system and the second specimen processing system, and includes a first transport line that transports a specimen rack in a first direction, a second transport line that transports a specimen rack holding a specimen in a second direction opposite to the first direction, a first connection bypass that connects the first transport line and the second transport line to each other and transports a specimen rack holding a specimen in a third direction, and a second connection bypass that connects the first transport line and the second transport line to each other and transports a specimen rack holding a specimen in a fourth direction opposite to the third direction;
• and
• an instruction unit that is capable of giving instruction such that the first specimen processing system or the second specimen processing system is set to be in an operation state or a pause state,
• wherein in the connection unit, ends of the first and second specimen processing systems and the lines are connected to each other so that the first specimen processing system, the first transport line, the second transport line, and the first connection bypass constitute a first loop structure, and the second specimen processing system, the first transport line, the second transport line, and the second connection bypass constitute a second loop structure, and
• wherein the specimen transport system further comprises:
• a control unit that performs control so that a specimen rack is transported by operating only a loop structure on a side where a system instructed to be set to be in an operation state by the instruction unit is disposed.