Patent ID: 8169122

Claim:
An apparatus for preparing biological samples, said apparatus comprising: a transducer assembly having a first natural frequency for vibration in an range of ultrasonic frequencies, said transducer assembly including: a piezoelectric transducer having a disc shape with a first center hole formed therein, said piezoelectric transducer being configured to vibrate within a range of ultrasonic frequencies; and a holding ring having a disc shape with a second center hole formed therein, said holding ring being coupled to said piezoelectric transducer with said second center hole aligned with said first center hole, said second center hole being smaller than said first center hole; a vial having a sidewall surrounding a chamber configured to receive and hold a biological sample therein, said sidewall being sized and shaped for insertion within said second center hole and to be coupled with said holding ring with an interference fit; and an oscillator driver in electrical communication with said piezoelectric transducer, said oscillator driver being configured to cause said piezoelectric transducer to vibrate at an excitation frequency proximate said first natural frequency.