Appeal No. 2002-1629 Page 3
Application No. 08/863,121
enable precise colorimetric analysis of the hemoglobin content in the
erythrocytes.” Id., page 2.
The specification discloses “cyanide-free reagents for use in the rapid
formation of a stable and detectable chromogen which is indicative of the amount
of hemoglobin present in a whole blood sample by conventional methodology.”
Page 1. The disclosed reagents comprise one of several specified quaternary
ammonium salts together with a hydroxylamine salt. See, e.g., page 3.
Discussion
Claim 25, the broadest claim on appeal, is directed to a “cyanide-free lyse
reagent” comprising at least one of certain quaternary ammonium salts in
combination with at least one of several hydroxylamine salts. Claim 25 also
specifies that the “reagent produces a chromogen having maximum absorbance
between 530 and 550 nm.”
The examiner rejected claims 26, 26, and 28 as obvious in view of Toda,
Ledis, and Bunn, and rejected claims 27 and 29 over those references further
combined with Naranayan. Since both rejections rely on the combination of
Toda, Ledis, and Bunn, we can consider them together.
The examiner characterized Toda as “teach[ing] an aqueous cyanide free
hemoglobin and leukocyte reagent which includes at least one quaternary
ammonium salt [albeit not one of those recited in the instant claims], . . . and an
oxidant capable of oxidizing heme in hemoglobin, such as sodium nitrite.”
Examiner’s Answer, page 5. He acknowledged that Toda “does not teach
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007