Apparatus and method for rapid disruption of cells or viruses

• US 20030066915A1
• Filed: 10/04/2001
• Published: 04/10/2003
• Est. Priority Date: 10/04/2001
• Status: Active Grant

• Current Assignee: Cepheid (Danaher Corporation)
• Original Assignee: Cepheid (Danaher Corporation)
• Inventors: Taylor, Michael T.
• Granted Patent: US 6,739,531 B2
• Time in Patent Office: Days
• US Class Current: 241/100
• CPC Class Codes: C12M 47/06 Hydrolysis; Cell lysis; Extraction of intracellular or cell wall material lysis of microorganisms C12N1/06; extracting or separating nucleic acids from biological samples C12N15/1003
• CPC Class Codes: C12N 1/066 by physical methods
• CPC Class Codes: G01N 1/286 involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising microtomes G01N1/06; pulverising in general B02C; mixing in general B01F

Abstract

An apparatus for disrupting cells or viruses comprises a container having a chamber for holding the cells or viruses. The chamber is defined by at least one wall having an external surface for contacting a transducer device. The transducer device has a vibrating surface for contacting the wall and for vibrating at an operating frequency and amplitude sufficient to generate pressure waves or pressure pulses in the chamber. The transducer device is coupled to the wall with a preload force sufficient to create a stress within the wall. The natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency by less than 50% of the operating frequency.

Claims

1. An apparatus for disrupting cells or viruses, the apparatus comprising:

a) a container having a chamber for holding the cells or viruses, wherein the container includes at least one wall defining the chamber, and wherein the wall has a surface external to the chamber;

b) a transducer device having a vibrating surface for contacting the external surface of the wall and for vibrating at an operating frequency and amplitude sufficient to generate pressure waves or pressure pulses in the chamber; and

c) means for coupling the surface of the transducer device to the wall with a preload force sufficient to create a stress within the wall;

wherein the natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency of the transducer device by less than 50% of the operating frequency of the transducer device.

2. The apparatus of claim 1, wherein the operating frequency is ultrasonic.

3. The apparatus of claim 2, wherein the transducer device comprises an ultrasonic horn having a tip for contacting the wall, and wherein the operating frequency is the resonant frequency of the horn.

4. The apparatus of claim 1, wherein the transducer device comprises a piezoelectric stack.

5. The apparatus of claim 1, wherein the wall is dome-shaped and convex with respect to the transducer device.

6. The apparatus of claim 1, wherein the wall is spherical and convex with respect to the transducer device.

7. The apparatus of claim 1, wherein the wall is flat.

8. The apparatus of claim 7, wherein the wall includes a central portion and stiffening ribs extending radially from the central portion.

9. The apparatus of claim 1, further comprising beads in the chamber for rupturing the cells or viruses.

10. The apparatus of claim 1, wherein the chamber has at least two ports positioned to permit flow of a sample through the chamber, and wherein the apparatus further comprises at least one filter in the chamber for capturing the cells or viruses as the sample flows through the chamber.

11. The apparatus of claim 1, wherein the natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency of the transducer device by less than 25% of the operating frequency of the transducer device.

12. The apparatus of claim 1, wherein the natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency of the transducer device by less than 10% of the operating frequency of the transducer device.

13. The apparatus according to any one of claims 1, 11, or 12, wherein the natural frequency of the wall, when the wall is stressed by the preload force, is less than or equal to the operating frequency of the transducer device.

14. The apparatus of claim 1, wherein the operating frequency of the transducer device is in the range of 20 to 120 kHz, the amplitude of the vibratory motion of the transducer device is in the range of 5 to 60 micrometers, and the preload force is in the range of 2 to 50 N.

15. The apparatus of claim 1, wherein the means for coupling the transducer device to the wall comprises a support structure for holding the container and the transducer device against each other such that the vibrating surface of the transducer device contacts the external surface of the wall, the support structure including an elastic body for providing the preload force.

16. The apparatus of claim 15, wherein the elastic body comprises a spring.

17. The apparatus of claim 1, wherein the means for coupling the vibrating surface of the transducer device to the wall comprises a clamp.

18. A method for disrupting cells or viruses, the method comprising the steps of:

a) holding a liquid or gel containing the cells or viruses in the chamber of a container, wherein the container includes at least one wall defining the chamber, and wherein the wall has a surface external to the chamber;

b) coupling a transducer device to the external surface of the wall with a preload force sufficient to create a stress within the wall; and

c) operating the transducer device at a frequency and amplitude sufficient to generate pressure waves or pressure pulses in the chamber;

wherein the natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency of the transducer device by less than 50% of the operating frequency of the transducer device.

19. The method of claim 18, wherein the operating frequency is ultrasonic.

20. The method of claim 18, wherein the transducer device comprises an ultrasonic horn having a tip for contacting the wall, and wherein the operating frequency is the resonant frequency of the horn.

21. The method of claim 18, wherein the transducer device comprises a piezoelectric stack.

22. The method of claim 18, wherein the wall is dome-shaped and convex with respect to the transducer device.

23. The method of claim 18, wherein the wall is spherical and convex with respect to the transducer device.

24. The method of claim 18, wherein the wall is flat.

25. The method of claim 24, wherein the wall includes a central portion and stiffening ribs extending radially from the central portion.

26. The method of claim 18, further comprising the step of agitating beads in the chamber to rupture the cells or viruses.

27. The method of claim 18, further comprising the step of capturing the cells or viruses on at least one filter positioned in the chamber by forcing a fluid sample containing the cells or viruses to flow through the chamber.

28. The method of claim 18, wherein the natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency of the transducer device by less than 25% of the operating frequency of the transducer device.

29. The method of claim 18, wherein the natural frequency of the wall, when the wall is stressed by the preload force, is equal to the operating frequency of the transducer device or differs from the operating frequency of the transducer device by less than 10% of the operating frequency of the transducer device.

30. The method according to any one of claims 18, 28, or 29, wherein the natural frequency of the wall, when the wall is stressed by the preload force, is less than or equal to the operating frequency of the transducer device.

31. The method of claim 18, wherein the operating frequency of the transducer device is in the range of 20 to 120 kHz, the amplitude of the vibratory motion of the transducer device is in the range of 5 to 60 micrometers, and the preload force is in the range of 2 to 50 N.