Patent ID: 8383066

Claim:
A filter vial kit, comprising: a tubular vial having longitudinal axis, a closed bottom, an open top and a cylindrical interior wall with a diameter D; a tubular piston with opposing distal and proximal ends with an opening in the distal end, the piston having a tubular wall defining an interior, the tubular wall having an outer diameter less than D, the piston further having a distal piston flange at or adjacent to the distal end of the piston and extending outward from the piston; a filter support at the distal end of the piston having openings through which fluid can flow into the interior of the piston during use; a retainer cup having a bottom and continuous sidewall with the sidewall extending between the bottom at a distal end of the cup and a proximal end of the cup, the cup sidewall having an interior diameter sufficiently smaller than the distal piston flange to allow the sidewall to pass over the distal piston flange, the bottom having an opening through which fluid can flow during use, the cup further having a cup seal extending outward from the proximal end of the cup a distance greater than the diameter D, the sidewall of the cup being sufficiently flexible to deform outward as the cup passes over the distal piston flange so the sidewall can have an outer dimension larger than diameter D at the location of the piston flange when the retainer cup passes over the distal piston flange; and a filter that is configured to fit between and be held between the retaining cup and the distal end of the piston when the proximal end of the retainer cup is placed over the distal end of the piston.