Ex Parte KRANTZ et al - Page 6

                Appeal No. 1996-3973                                                                                                         
                Application No. 08/048,657                                                                                                   

                intermediate porous glass fiber disc 20; a lower porous glass fiber disc 22; a porous filter                                 
                membrane 26 (e.g., a cellulose acetate membrane); and a transparent film membrane 30, wherein                                
                a first reagent is absorbed on discs 18, 20 and 22 and a second reagent is freeze-dried on the inner                         
                surface of membrane 30 (Fig. 3; col. 4, lines 38-61).  EXAMPLE 3 (col. 6) illustrates a test                                 
                device for determining hexokinase wherein the upper glass fiber discs are impregnated with                                   
                NADP, G-6-P, magnesium acetate, PMS and NBT (an indicator reagent which reacts to form a                                     
                detectable formazan dye), while the lower transparent film membrane is coated with G-6-PDH,                                  
                dextran and, if necessary, hexokinase.                                                                                       
                        The examiner states “[t]he claims differ from Daffern above in that the claims include                               
                multiple layers with a single aligned aperture” and concludes that it would have been obvious to                             
                one of ordinary skill in the art “to employ the multiple layer features of the test strip apparatus of                       
                Moyer in the test strip of Daffern because related types of reactions are performed by the test                              
                strips of both references” (answer, page 5).  According to the examiner, “the teachings of the                               
                references were clearly in the public domain and one of ordinary skill in this art known of these                            
                references could have selected as the Appellants have done” (answer, page 11).                                               
                        However, the examiner has not pointed out where either Daffern or Moyer discloses or                                 
                suggests the specific juxtaposition of (i) an apertured inert backing layer overlying (ii) a one or                          
                two layered “reactive unit” comprising a spreading agent and an analyte-reactive reagent and (iii)                           
                an indicator layer comprising an indicator reagent impregnated into a porous substrate.  Both                                

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