Appeal No. 2006-0258 Page 13
Application No. 09/755,747
the formation or dissociation of a complex (abstract). . . .” In this regard, the
examiner finds (Answer, pages 6-7), the complex taught by Wittwer consists of:
(a) a single strand of a DNA sequence . . .,
(b) an oligonucleotide specific for the single stranded DNA
sequence. . .,
(c) a marker specific for the duplex structure of (a) plus (b)
which forms a complex with the said duplex and reacts uniquely
when interacting within the duplex.
In this regard, the examiner focuses attention on the fluorescent dye
SYBR green. Id.
According to the examiner (Answer, page 7), Wittwer’s method comprises:
(1) “monitoring fluorescence while changing temperature at a
rate of 0.1 degree C/second.” . . .
(2) continually measuring an output signal indicative of
interaction of the marker with duplex formed from the strand (a) and
probe (b) . . . and
(3) recording the conditions at which a change in reaction
output signal occurs which is attributable to formation or
dissociation of the complex and is thereby correlated with the
strength with which the probe (b) has hybridized to the single strand
(a) . . . .
Based on this evidence the examiner finds (Answer, bridging paragraph, pages
8-9),
It would have been prima facie obvious to one of ordinary skill in
the art at the time the invention was made to utilize the markers of
Wittwer in the mutation detection method of Stimpson since Wither
states “SYBRTM Green I is a preferred double strand specific dye
for fluorescence monitoring of PCR, primarily because of superior
sensitivity, arising from greater discrimination between double
stranded and single stranded nucleic acid. SYBRTM Green I can be
used in any amplification and is inexpensive. In addition, product
specificity can be obtained by analysis of melting curves . . . .”
Thus, an ordinary practitioner would have been motivated to use
SYBRTM Green I in the melting curve analytical method of Stimpson
since Wittwer teaches that this intercalator is superior in sensitivity,
is useful in the particular assay employed by Stimpson since the
waveguides would detect the fluorescent label and is inexpensive.
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