Cell lysis systems and methods

1 . A cell lysis system comprising:

a sample container configured to contain a sample of cells, the sample container including a tube having an interior space and a closed lower end for holding the sample of cells within the interior space, the sample of cells being in a liquid solution which is fully contained in the interior space within the sample container;

a sonication capsule including:

a housing having a side wall, a base and a cover opposite to the base, the cover including an opening which receives at least a part of the tube of the sample container, the at least a part of the tube of the sample container closing and sealing the opening in the cover;

a sonication chamber provided within the housing, the sonication chamber being at least partly filled with an ultrasonic wave transfer medium, the ultrasonic wave transfer medium being a liquid having an acoustic impedance, wherein the sample container projects into the ultrasonic wave transfer medium and the ultrasonic wave transfer medium is retained within the sonication chamber by the part of the tube of the sample container which closes and seals the opening in the cover of the housing, the sample container containing the sample of cells in the liquid solution within the interior space of the sample container separate from the ultrasonic wave transfer medium present in the sonication chamber;

an ultrasonic transducer within the sonication chamber positioned at the closed lower end of the sample container, the ultrasonic transducer being in contact with the ultrasonic wave transfer medium in the sonication chamber and outside of the sample container, the ultrasonic transducer not contacting the liquid solution with the sample of cells contained within the sample container;

a plurality of electrical terminals connected electrically to the ultrasonic transducer; and

a driver apparatus, the sonication capsule being releasably attached to the driver apparatus, the driver apparatus including:

a plurality of driver output terminals which are connected electrically to the plurality of electrical terminals of the sonication capsule to provide an electrical connection between the driver apparatus and the sonication capsule to drive the ultrasonic transducer within the sonication capsule;

an AC driver which generates an AC drive signal at a predetermined frequency and outputs the AC drive signal at the driver output terminals to drive the ultrasonic transducer within the sonication capsule;

an active power monitoring arrangement which monitors the active power used by the ultrasonic transducer when the ultrasonic transducer is driven by the AC drive signal, wherein the active power monitoring arrangement provides a monitoring signal which is indicative of an active power used by the ultrasonic transducer;

a processor which controls the AC driver and receives the monitoring signal from the active power monitoring arrangement; and

a memory storing instructions which, when executed by the processor, cause the processor to:

A. control the AC driver to output an AC drive signal to the ultrasonic transducer at a predetermined sweep frequency;

B. calculate the active power being used by the ultrasonic transducer based on the monitoring signal;

C. control the AC driver to modulate the AC drive signal to maximize the active power being used by the ultrasonic transducer;

D. store a record in the memory of the maximum active power used by the ultrasonic transducer and the sweep frequency of the AC drive signal;

E. repeat steps A-D for a predetermined number of iterations with the sweep frequency incrementing with each iteration such that, after the predetermined number of iterations has occurred, the sweep frequency has been incremented from a start sweep frequency to an end sweep frequency;

F. identify from the records stored in the memory the optimum frequency for the AC drive signal which is the sweep frequency of the AC drive signal at which a maximum active power is used by the ultrasonic transducer; and

G. control the AC driver to activate the ultrasonic transducer for a first predetermined length of time, deactivate the ultrasonic transducer for a second predetermined length of time and activate the ultrasonic transducer for a third predetermined length of time to alternately output an AC drive signal to the ultrasonic transducer at the optimum frequency when the ultrasonic transducer is activated and not output the AC drive signal to the ultrasonic transducer when the ultrasonic transducer is deactivated, the ultrasonic transducer generating ultrasonic waves in the ultrasonic wave transfer medium within the sonication chamber when the ultrasonic transducer is activated, the ultrasonic waves being transferred by the ultrasonic wave transfer medium from the ultrasonic transducer to the sample container to lyse the sample of cells in the liquid solution contained within the sample container, the lysed sample of cells remaining within the sample container and the liquid solution with the lysed sample of cells not being in contact with the ultrasonic transducer.

2 . The system of claim 1 , wherein the active power monitoring arrangement comprises:

a current sensing arrangement which senses a drive current of the AC drive signal driving the ultrasonic transducer, wherein the active power monitoring arrangement provides a monitoring signal which is indicative of the sensed drive current.

3 . The system of claim 1 , wherein the memory stores instructions which, when executed by the processor, cause the processor to:

repeat steps A-D with the sweep frequency being incremented from a start sweep frequency of 2800 kHz to an end sweep frequency of 3200 kHz.

4 . The system of claim 1 , wherein the memory stores instructions which, when executed by the processor, cause the processor to:

in step G, when activating the ultrasonic transducer, control the AC driver to output an AC drive signal to the ultrasonic transducer at a frequency which is shifted by between 1-10% of the optimum frequency.

5 . The system of claim 1 , wherein the AC driver modulates the AC drive signal by pulse width modulation to maximise the active power being used by the ultrasonic transducer.

6 . The system of claim 1 , wherein the memory stores instructions which, when executed by the processor, cause the processor to:

alternately output the AC drive signal when the ultrasonic transducer is activated and to not output the AC drive signal when the ultrasonic transducer is deactivated according to an operating mode selected from:

First

Second

predetermined

predetermined

Operating

length of time

length of time

mode

(seconds)

(seconds)

 1

4

2

 2

3

2

 3

2

2

 4

1

2

 5

1

1

 6

2

1

 7

3

1

 8

4

1

 9

4

3

10

3

3

11

2

3

12

1

3

7 . The system of claim 1 , wherein the driver apparatus comprises a first interference fit attachment and the sonication capsule comprises a second interference fit attachment, and wherein the first interference fit attachment releasably attaches to the second interference fit attachment to releasably attach the sonication capsule to the driver apparatus.

8 . The system of claim 1 , wherein the cell lysis device further comprises a transducer holder which is coupled to the base of the housing, the transducer holder carrying and at least partly surrounding the ultrasonic transducer.

9 . The system of claim 1 , wherein the ultrasonic wave transfer medium is a liquid which has a higher acoustic impedance than water.

10 . The system of claim 1 , wherein the ultrasonic wave transfer medium is vegetable glycerine.

11 . The system of claim 1 , wherein the housing of the sonication capsule is cylindrical, the base of the sonication capsule is generally circular and positioned at a first end of the sonication capsule and the cover of the sonication capsule is circular and positioned at a second end of the sonication capsule opposite to the first end of the sonication capsule.

12 . The system of claim 1 , wherein the sonication capsule is a disposable, single-use capsule.

13 . The system of claim 1 , wherein the sonication chamber is pre-filled with the ultrasonic wave transfer medium.