Development of a novel polyclonal antibody-based immunoassay for the quantitation of non-albumin urinary proteins

Abstract

Background: Better diagnostic methods to detect urinary proteinuria or albuminuria, important indicators of diabetic kidney disease, are needed. Here, we describe the development and performance qualification of a new immunoassay for the quantitation of non-albumin urinary proteins of 20 to 90 kilodaltons. Methods: Urinary proteins, purified from pooled, 24-hour, diabetic urines, were immunoabsorbed to remove albumin, electrophoretically characterized, and identified by mass spectrometry. Sheep antiurinary protein polyclonal antibodies were immunoabsorbed to remove albumin reactivity. Major immunoreactive specificities of the polyclonal antibody were identified by Western blot. A polyclonal ..