Collection Device and Method

A passive flotation method for separating particles from a sample of matter, which comprises the steps of:

• mixing the sample of matter with a flotation solution having a predetermined specific gravity in a collection device to form an emulsion therein, the particles being suspended in the emulsion, the collection device including a collection tube and a particle accumulating plug, the collection tube having a sidewall including an inner surface, and defining a tube inner bore and a top opening in communication with the tube inner bore, the particle accumulating plug being mounted in the tube inner bore of the collection tube through the top opening thereof and axially movable within the bore, the particle accumulating plug having an outer sidewall defining a plug inner bore, and an inner wall disposed within the plug inner bore, the inner wall of the plug being conically-shaped to define an inverted funnel having an apex, the conically-shaped inner wall having a pipetting port;
• advancing the particle accumulating plug axially into the tube inner bore of the collection tube until the surface of the emulsion therein is substantially level with the pipetting port of the particle accumulating plug;
• allowing the emulsion within the collection tube of the collection device to rest for a predetermined period of time so that particles in the emulsion rise in the collection tube and accumulate within the funnel to provide a fluid containing a concentrated quantity of separated particles;
• inserting the tip of the pipette into the pipetting port of the particle accumulating plug;
• and
• aspirating into the tip of the pipette through the pipetting port a predetermined volume of the fluid containing a concentrated quantity of separated particles for subsequent analysis.

A centrifuge flotation method for separating particles from a sample of matter, which comprises the steps of:

• mixing the sample of matter with a flotation solution having a predetermined specific gravity in a collection device to form an emulsion therein, the particles being suspended in the emulsion, the collection device including a collection tube and a particle accumulating plug, the collection tube having a sidewall including an inner surface, and defining a tube inner bore and a top opening in communication with the tube inner bore, the particle accumulating plug being mounted in the tube inner bore of the collection tube through the top opening thereof and axially movable within the bore, the particle accumulating plug having an outer sidewall defining a plug inner bore, and an inner wall disposed within the plug inner bore, the inner wall of the plug being conically-shaped to define an inverted funnel having an apex, the conically-shaped inner wall having a pipetting port;
• advancing the particle accumulating plug axially into the tube inner bore of the collection tube until the surface of the emulsion therein is substantially level with the pipetting port of the particle accumulating plug;
• centrifuging the emulsion within the collection tube of the collection device for a predetermined period of time so that during or after centrifugation particles in the emulsion having a specific gravity which is less than the specific gravity of the flotation solution rise in the collection tube and accumulate within the funnel defined by the conically-shaped inner wall of the particle accumulating plug to provide a fluid containing a concentrated quantity of separated particles;
• inserting the tip of the pipette into the pipetting port of the particle accumulating plug;
• and
• aspirating into the tip of the pipette through the pipetting port a predetermined volume of the fluid containing a concentrated quantity of separated particles for subsequent analysis. will rise in the collection tube and accumulate within the funnel defined by the conically-shaped inner wall of the particle accumulating plug to provide a fluid thereat containing a concentrated quantity of separated particles.