Systems for collecting fluid samples having select concentrations of particles

• US 6,318,190 B1
• Filed: 08/20/1999
• Issued: 11/20/2001
• Est. Priority Date: 11/01/1996
• Status: Expired due to Term

• Current Assignee: Cytyc Corporation (Hologic Incorporated)
• Original Assignee: Cytyc Corporation (Hologic Incorporated)
• Inventors: Lapen, Daniel C., Festel, Charles A., Radcliffe, Gail E.
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US09/372,146
• Time in Patent Office: 823 Days
• Field of Search: 738/632.1, 738/632--86, 73/617.3, 738/630--86, 738/643.1
• US Class Current: 73/863.02
• CPC Class Codes: G01N 1/2813 Producing thin layers of samples on a substrate, e.g. smearing, spinning-on G01N1/30 takes precedence
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 1/4077 by other techniques involving separation of suspended solids
• CPC Class Codes: G01N 15/0618 of the filter type G01N15/0643 takes precedence
• CPC Class Codes: Y10T 436/107497 Preparation composition [e.g., lysing or precipitation, etc.]
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

Instruments and processes according to the invention provide for the preparation of a fluid sample that has a substantially known concentration of a select particulate matter. In one aspect, the invention is understood as laboratory instruments for sample preparation. These instruments can include a filter that is submersible within a fluid suspension of particulate matter. To collect particulate matter from the fluid suspension, the instruments can cause a fluid flow that pulls fluid across the filter to trap particulate matter against one surface of the filter. The instruments can then remove the filter from the fluid suspension and dispose the filter above a collection vessel such that the side of the filter that is carrying particulate matter is positioned above the opening of the collection vessel. The laboratory instruments can then send a collection fluid through the filter in a direction opposite to the original fluid flow, thereby washing the particulate matter off the filter and into the collection vessel. The laboratory instruments according to the invention can provide samples having a known concentration by passing a known volume of collection fluid through the filter, thereby trapping the collected particulate matter within a known volume of collection fluid.

Claims

1. An apparatus for collecting a fluid sample having a predetermined concentration of particles, comprising:

a filter comprising a first side and a second side and pores of sufficient size to allow fluid flow but not particle flow;

a pressure source capable of applying pressure across the in both directions;

a pressure monitor coupled to said pressure source;

an actuator for removing said filter and said particles collected thereon from said fluid suspension; and

a processor connected to said pressure source and said pressure monitor, the processor being adapted to control said pressure source in response to input from said pressure monitor such that

a) pressure is applied across the filter to cause fluid sample to flow through the filter in the direction from the first side of the filter to the second side of the filter resulting in accumulation of particles on the first side of the filter,

b) pressure is terminated upon the accumulation of a selected quantity of particles on the first side of the filter, and

c) pressure is applied across the filter in the direction from the second side to the first side resulting in the detachment of the collected particles from the first side of the filter.

2. The apparatus of claim 1, further comprising an intake port and an evacuation port, wherein the filter spans the intake port.

3. The apparatus of claim 1, further comprising at least one transverse edge adapted to facilitate the formation of a drop of fluid.

4. The apparatus of claim 3, wherein the apparatus comprises two transverse edges.

5. The apparatus of claim 1, wherein the actuator is adapted to apply a rotational force on the apparatus.

6. The apparatus of claim 1, wherein the pore size of the filter is about 0.2 to about 20 microns.

7. The apparatus of claim 1, wherein the filter is made from material selected from the group consisting of cellulose, nylon, polyester, and teflon.

8. The apparatus of claim 1, wherein said first pressure source provides pressure in a series of pulses.

9. The apparatus of claim 1, further comprises a first chamber and a second chamber, the filter being disposed between the first and second chambers such that a fluid is forced from the first chamber to the second chamber.

10. The apparatus of claim 9, further comprising a second pressure source adapted to provide positive pressure across the filter from the second side to the first side.

11. The apparatus of claim 10, further comprising a collection fluid source comprising a volumetric control for introducing a selected volume of collection fluid into the second chamber.

12. The apparatus of claim 10, wherein the processor is adapted to execute the following series of events:

a) providing the sample fluid to the first chamber,

b) causing the first pressure source to provide pressure across the filter in the direction from the first side to the second side,

c) receive input from the pressure monitor relating to the pressure across the filter,

e) determining the amount of particles accumulated on the first side of the filter

f) terminating the pressure provided by the first pressure source once a selected quantity of particles have accumulated on the first side of the filter,

g) causing the fluid collection source to introduce a selected volume of collection fluid into the second chamber of the particle collection device,

h) causing the second pressure source to provide pressure across the filter in the direction from the second side to the first side, thereby disengaging substantially all of the particles from the first side of the filter and collecting the selected quantity of particles within the selected volume of collection fluid.