This manuscript describes the problems inherent in combining immunoprecipitation of lipoprotein lipase (LPL) with its detection by Western blot, and how these problems can be circumvented by the preparation of suitable immunoreagents. These reagents used during the immunoprecipitation step, include Fab fragments of the primary antibody (chicken anti-bovine LPL), and a covalently linked immunomatrix of the secondary antibody (rabbit anti-chicken IgG). The use of these reagents in conjunction with Western blot detection virtually eliminates the problem of non-relevant protein detection when analyzing LPL from complex biological samples. Moreover, this approach can be adapted to detect any protein with the same inherent problems as LPL, such as hepatic lipase.