Petchek heartworm pf antigen test

All antigen testing was conducted using commercial assays according to manufacturers’ instructions, with the exception that samples were tested before and after heat treatment on each assay. For heat treatment, serum samples were placed in a heat block at 103°C for 10 minutes, the resultant coagulum centrifuged, and the supernatant used in each commercial assay. Test kits evaluated before and after heat treatment included enzyme linked immunosorbent assay (ELISA) in microtiter plate formats (DiroCHEK®, Synbiotics Corporation, Zoetis; PetChek® Heartworm PF Antigen Test, IDEXX Laboratories, Inc.), membrane bound ELISAs (SNAP® Feline Heartworm® Test, IDEXX Laboratories, Inc.), and lateral flow immunochromatographic tests (WITNESS® HW, Synbiotics Corporation, Zoetis). In addition, O.D. readings were obtained by spectrophotometry before and after heat treatment for one of the microtiter plate assays (PetChek® Heartworm PF Antigen Test, IDEXX Laboratories, Inc.) according to manufacturer’s directions.

Optical density from microtiter plate assay (PetChek® Heartworm PF Antigen Test, IDEXX Laboratories, Inc.) and mean O.D. of triplicate antibody tests (ANTECH Diagnostics) for each cat for all days on which antigen was detected in any one cat and for cats on each of three individual study days (study days 168, 196, and 224) were compared using one-way ANOVA in Excel 2007 (Microsoft Office) with significance assigned at alpha = 0.05 [13 ]. An antigen/antibody ratio was also determined for each cat on days 168, 196, and 224 using O. D. and mean O. D., respectively.