Development of a Gold Immunochromatographic Assay Method Using Candida Biofilm Antigen as a Bioreceptor for Candidiasis in Rats

Abstract

The gold immunochromatography assay (GICA), a new immunochromatography technique, uses a nitrocellulose membrane as a carrier and a colloidal gold-labeled antigen or antibody as a tracer (bioreceptor). This technology has many advantages over other immunoassays, including its simplicity, rapidity, cheapness, and the lack of a requirement for special training or expensive equipment, and it can be used to detect either antigens or antibodies. Therefore, we chose to develop this method for the diagnosis of candidiasis in Indonesia. The objective of the present study was to develop a diagnostic test for Candida albicans in rats using the GICA method. GICA bioreceptors were developed from biofilm antigens isolated from biofim Candida albicans grown on the surface of nitrocellulose membranes. The formation of biofilms was confirmed using scanning electron microscopy. Antigen levels as bioreceptors were optimized by using the immuno dot method. The samples to be analyzed were antibody serum, in the form of blood serum samples from heart mice that have been induced to become candidiasis. To this end, we optimized the antigen and antibody volumes necessary to make this diagnosis. The results show that the optimum concentration of antigen to be used in the test is 2.5 μg/μL and the optimum volume of antibody is 10 μL. The control rats produced a single red stripe on the control line and the candidiasis rat samples produced a double red stripe, with the bottom line being the control line and the upper line the test line. The test chip was successfully used for the diagnosis of candidiasis in rats and given the name “Candiday Kit.”. We anticipate that this test will be suitable for the diagnosis of candidiasis in humans

Keywords

• candidiasis
• rat
• gold immunochromatography assay
• antigen
• biofilm
• candida albicans