Methods and apparatus for treating samples with acoustic energy

Abstract

This invention relates to systems and methods for applying acoustic energy to a sample. According to one aspect of the invention, a system comprises a housing, a chamber for receiving the sample, an acoustic energy source for providing a focused acoustic field to the sample according to a treatment protocol, a processor for determining the treatment protocol, a sensor for detecting information about the sample, and a user interface for communicating with a user.

1 . A method for fragmenting a sample contained in a vessel, comprising:
 providing a vessel containing a sample;   pressurizing the sample such that a pressure within the vessel is greater than one atmosphere;   transmitting focused acoustic energy having a focal zone to the sample through a wall of the vessel;   forming a plurality of cavitation bubbles in the sample while the sample is under a pressure of greater than one atmosphere by, at least in part, exposure of the sample to the focal zone of the focused acoustic energy;   collapsing the plurality of cavitation bubbles while the sample is under a pressure of greater than one atmosphere so as to produce increased shear forces within the sample consequent to cavitation bubble collapse; and   fragmenting at least a portion of the sample by, at least in part, exposure of the sample to the shear forces.   
     
     
         2 . The method of  claim 1 , wherein the pressure within the sample is between 2 atmospheres and 4 atmospheres. 
     
     
         3 . The method of  claim 2 , wherein the pressure within the sample is about 3 atmospheres. 
     
     
         4 . The method of  claim 1 , wherein pressurizing the sample comprises adding at least one of compressed air, nitrogen, argon, helium, and inert gas to a space within the vessel. 
     
     
         5 . The method of  claim 1 , wherein pressurizing the sample comprises reducing a volume of the vessel. 
     
     
         6 . The method of  claim 1 , wherein the focused acoustic energy comprises a 10% duty cycle and 200 cycles per burst. 
     
     
         7 . The method of  claim 1 , wherein the sample comprises DNA strands. 
     
     
         8 . The method of  claim 1 , wherein the sample comprises crystalline particles. 
     
     
         9 . The method of  claim 8 , wherein the crystalline particles comprise hydroxyapatite. 
     
     
         10 . The method of  claim 1 , wherein the sample comprises yeast spores, and wherein fragmenting the sample causes lysis of at least a portion of the yeast spores. 
     
     
         11 . The method of  claim 1 , wherein shear forces consequent to cavitation bubble collapse aid in retaining a portion of the sample in the focal zone. 
     
     
         12 . The method of  claim 1 , wherein the step of fragmenting at least a portion of the sample includes lysing microbial organisms, and wherein a rate of lysis of the microbial organisms while the sample is under a pressure greater than one atmosphere is greater than while the sample is under atmospheric pressure. 
     
     
         13 . The method of  claim 1 , wherein the step of fragmenting at least a portion of the sample includes homogenizing tissue, and wherein a rate of homogenization of the tissue while the sample is under a pressure greater than one atmosphere is greater than while the sample is under atmospheric pressure. 
     
     
         14 . The method of  claim 1 , wherein the step of fragmenting at least a portion of the sample includes fragmenting DNA, and wherein a rate of fragmentation of the DNA while the sample is under a pressure greater than one atmosphere is greater than while the sample is under atmospheric pressure. 
     
     
         15 . A method of fragmenting a DNA sample contained in a vessel, comprising:
 providing vessel containing a sample, the sample containing DNA strands having a first length;   pressurizing the sample such that a pressure within the vessel is greater than or equal to 2 atmospheres;   transmitting focused acoustic energy having a focal zone to the sample through a wall of the vessel;   forming a plurality of cavitation bubbles in the sample by, at least in part, exposure of the sample to the focal zone of the focused acoustic energy;   collapsing at least a portion of the cavitation bubbles so as to produce shear forces within the sample consequent to cavitation bubble collapse; and   fragmenting at least a portion of the DNA strands by, at least in part, exposure of the sample to the shear forces, such that the majority of the DNA strands in the sample have a second length between 100 base pairs and 500 base pairs.   
     
     
         16 . The method of  claim 15 , wherein the pressure within the vessel is about 3 atmospheres. 
     
     
         17 . The method of  claim 16 , wherein the focused acoustic energy is transmitted for a treatment duration at least 180 seconds. 
     
     
         18 . The method of  claim 16 , wherein the focused acoustic energy is transmitted for a treatment duration of 360 seconds. 
     
     
         19 . The method of  claim 18 , wherein the second length is between 100 base pairs and 375 base pairs. 
     
     
         20 . The method of  claim 15 , wherein the sample comprises lambda DNA in 1 mM EDTA. 
     
     
         21 . The method of  claim 15 , wherein pressurizing the sample comprises adding at least one of compressed air, nitrogen, argon, helium, and inert gas to a space within the vessel. 
     
     
         22 . The method of  claim 15 , wherein pressurizing the sample comprises reducing a volume of the vessel. 
     
     
         23 . The method of  claim 15 , wherein the focused acoustic energy comprises a 10% duty cycle and 200 cycles per burst.