Ultrafiltration unit

Claim 1

An ultrafiltration unit for use with a syringe having a tapered snout, consisting of: a housing having a dome-shaped upper part provided with a flange at its peripheral edge and a funnel-shaped lower part provided with a flange at its peripheral edge which are airtighty connected and sealed together along the peripheral flanges, said upper part having a single inlet pipe at its top and a chamber therein for forcing a sample liquid and air in the chamber, a bore of the inlet pipe being partially flared from the intermediate toward its free end for allowing to engage with the snout of the syringe and being provided with a shoulder portion adjacent below the flared bore section, said lower part having an internal slanted surface and a single outlet pipe at its apex, a disc-shaped ultrafilter internally disposed in the housing held between the peripheral flanges of the upper and lower parts of the housing and supported on a plurality of radial support ribs integrally formed on the slanted surface of the lower part of the housing, and a check valve provided in the inlet pipe, said check valve being partially fixed to the shoulder portion in the inlet pipe so as to be bendable downwardly toward the chamber or thrustable against the shoulder portion, whereby a sample liquid and air can be forced into the chamber of the upper part of the housing while escape of the air is blocked.