Bubble recycling and ultrasonic cell lysis in a stationary exposure vessel.
An exposure system producing interleafed pulses of 1-MHz ultrasound from balanced, opposing transducers was used to test the bubble recycling hypothesis (as formulated with respect to rotating exposure vessels) in a stationary exposure vessel containing P388 cell suspensions. Cell lysis was measured in cell suspensions which had been exposed or sham-exposed to 1-MHz ultrasound (5 W/cm2 spatial peak pulse average intensity) delivered in continuously alternating, opposing pulses. The opposing pulse cycle frequency (i.e., gating frequency) varied from 0.1 Hz to 100 kHz, corresponding to single pulse durations ranging from 5 microseconds to 5 s. Unequivocal support for the bubble recycling hypothesis was obtained. Lytic yield increased as the gating frequency increased, passing through a maximum at gating frequencies of 100 Hz-1 kHz. As the gating frequency increased further, lytic yield declined rapidly. The results are discussed in relation to recent theoretical estimates of bubble translation speeds in an ultrasound field, and are found to be consistent with those estimates.
Brayman
A A
AA
Department of Biophysics, School of Medicine and Dentistry, University of Rochester, New York 14642.
Azadniv
M
M
Miller
M W
MW
Chen
X
X
D000818:Animals; D002415:Cats; D004179:Cobra Cardiotoxin Proteins; D046508:Culture Techniques; D014159:Transducers; D014463:Ultrasonography
D004179:Cobra Cardiotoxin Proteins