Abstract: An apparatus and a method are provided for assembling micro-filter units having a barrel, a plug adapted to be inserted in the barrel, and a filter disc clamped between the barrel and the plug, which are characterized in that the filter disc is punched out and seated in the barrel in a single stroke of a punch.

Abstract: Microliter sized samples of filtered urine or the like are obtained by taking up a few drops of urine into a bulb-type micro-syringe inserting the nozzle thereof tightly into the inlet passageway of a micro-filter having a disc of filter paper as the filtering medium held firmly between the inlet passageway and an outlet passageway and squeezing the bulb of the micro-syringe to force the urine through the filter paper. The outlet passageway is constricted in size and shape to discharge the filtered urine in drops. The filtered urine then comes through in uniform drops of predetermined size which are utilized in a testing procedure, for example, in a direct agglutination test for pregnancy.

Abstract: An apparatus and a method are provided for assembling micro-filter units having a barrel, a plug adapted to be inserted in the barrel, and a filter disc clamped between the barrel and the plug, which are characterized in that the filter disc is punched out and seated in the barrel in a single stroke of a punch.