Appeal No. 2002-0780 Page 3
Application No. 09/128,340
next to a sonicator probe), and placing into the first liquid a vessel comprising
cells in a second liquid (i.e.[,] tubes containing the cells within another liquid,
such as residual water or buffer solution or detergent solution).” In addition, the
examiner finds that Buck teaches the “use of a liquid having an alkaline pH (i.e.[,]
pH 8.3) for disrupting cells…” and describe well know surfactants “Triton X-100
and Tween to be useful for cell disruption.”
As we understand the reference, Buck was interested in identifying a
methodology for isolating DNA from Mycobacterium tuberculosis for amplification
by the polymerase chain reaction. See Title and Abstract. Buck studied four
separate methods; (1) treatment with proteinase K and nonionic detergents, (2)
boiling with nonionic detergents, (3) freezing and thawing and (4) sonication. For
the sonication method, Buck teaches (bridging sentence, pages 1331-1332),
“tubes [containing cells suspended in distilled water] were placed in a plastic rack
that was floated in a dish of water next to the sonicator probe … and sonicated
for 30 min at 45 W.” While the Buck refers to a PCR buffer comprising “a liquid
having an alkaline pH,” “Triton X-100 and Tween,” this PCR buffer was used in
methods (1)-(3) above, and was not used in the sonication method taught by
Buck. Buck concludes (page 1333, column 1):
Our results confirm that these simplified methods [(1)-(3) above]
are capable of releasing DNA for amplification but suggest that
these methods are relatively ineffective, since the sensitivity of
detection was only down to about 103 organisms.
The sonication procedure, on the other hand, was capable of
detecting as few as 10 to 100 organisms. It appears that enough
ultrasonic energy is transmitted through the walls of the
microcentrifuge tubes to effectively disrupt the mycobacteria.
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