Appeal No. 1997-4145
Application No. 08/361,328
Here, the specification fails to provide direction or working examples for
controlling and/or varying the amount of stretching of a DNA molecule within defined
limits, e.g., "between about 0.40 :m and 0.45 :m" as required by claim 37. According
to the specification "a fluid should be added to create a suspension in order to
affectively stretch out the DNA" and these fluids, including mixtures of organic solvents
and aqueous media, "would be expected to have the effect of altering the rate and
amount of extension" (p. 10, last para.). However, the specification provides no further
guidance as to how to tailor a specific fluid to obtain a specific amount of DNA
extension in a reasonable and predictable manner. The specification also notes that
"[d]ifferences in surface material and surface tension of the DNA solution may affect the
rate of streaming and the ultimate extension of the DNA molecule" (p. 11, ll. 11-13) but
gives little, if any, further guidance as to the relationship between different support
surfaces, different chemical coatings or other modifications of the support surface or
surface tension vis-a-vis the stretching of the DNA molecule within controlled limits
without breakage. Moreover, the specification states, on the one hand, that "[t]he
gravitational streaming method involves tilting the supporting surface at an angle which
will efficiently extend the DNA" (p. 11, ll. 6-8) and, on the other hand, that "[t]he effect of
the angle [of tilt] on the DNA stretching process had an insignificant effect on maps <40
kb" (p. 23, ll. 19-20). Finally, the prior art, i.e., Matsumoto, indicate that fluid selection,
sample volume, and shear stress significantly affected morphology of DNA
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