Abstract: A sugar chain synthesizer comprising one or more reaction columns packed with immobilized glycosyltransferase and/or glycosidase; one or more separation means, arranged downstream from the reaction columns, for separating reaction products, unreaction products and byproducts contained in the solution eluted from the reaction columns; a first pump for feeding a primer of water soluble polymer and buffer solution to the reaction columns through a first selector valve; a second pump for feeding a buffer solution and sugar nucleotide solution to any one of the reaction columns through a second selector valve; one or more circulation flow paths connecting between a flow path downstream from the separation means and a flow path upstream from each of the reaction columns; and a third selector valve, arranged between the separation means and one or more circulation flow paths, for selective connection between the separation means and a desired circulation flow path.

Abstract: A plunger pump for supplying solution in accordance with an extrusion action of a plunger within a pump chamber. The plunger pump includes a cleaning chamber sealed by a seal member around and relative to the plunger, with a cleaning liquid inlet-side flow conduit and a cleaning liquid outlet-side flow conduit for communicating with the cleaning chamber, respectively. A mechanism isolates one of the inlet- and outlet-side flow conduits from the atmosphere and releases the other to an atmosphere under a condition where the cleaning liquid inlet- or outlet-side flow conduits are filled with the cleaning liquid. If the seal member in sliding contact with the plunger is degraded or aged, it is possible to observe a leakage of the liquid from the pump chamber along a sealing face between the seal member and the plunger.