Development of a colloidal gold-based immunochromatographic test strip for screening of microalbuminuria.

A rapid immunochromatography (ICG) assay based on antibody colloidal gold nanoparticles specific to human serum albumin (HSA) was developed, and its applications for primary screening of HSA in the urine were evaluated. A monoclonal antibody (MAb) specific to HSA was produced from cloned hybridoma cells (EMRC1) and used to develop an ICG strip. The nanocolloidal gold, with an average particle diameter of 20 nm, was synthesized and labeled MAb as the detection reagent. An antibody colloidal gold probe was applied on the conjugate pad, and HSA antigen was immobilized to a nitrocellulose membrane as the capture reagent to prepare the ICG strip test. This test required only 10 min to accomplish a semiquantitative detection of albumin. The sensitivity to urinary albumin was found to be approximately 20 μg/mL, and the analytical range was 20-25 μg/mL. The reliability of the testing procedures was examined by carrying out the ICG strip test with 40 urine samples and comparing the results of these tests with those obtained via immunoturbidimetry. The ICG strip was adequately sensitive and accurate for a rapid screening of HSA in the urine.