Immunosorbent assay using gold colloid cluster technology for determination of IgEs in patients’ sera

Abstract

This study focuses on the development of a sensitive and simple cluster-linked immunosorbent assay (CLISA) using gold colloidal cluster labeling for determination of proteins such as antigens (Ags) or antibodies (Abs). Abs for detection can be labeled with gold colloid clusters (GCCs). The Fc domain of the Abs binds to the clusters, and the Fab domain to the Ag on a nitrocellulose membrane or a microtiter plate as a support for dot-blotting. The signal of positive interaction between GCC-labeled Abs and its dotted Ag is detectable by the naked eye and can be quantified by comparison to a color scale prepared from a dilution series of known sample concentrations. The colored reaction product is stable for prolonged periods and does not fade, making this method a simple, fast, and convenient means for detection of Ag or Ab biorecognitions and an alternative to enzyme-linked immunosorbent assay. Several interactions between different Ags or Abs (eg, β-lactoglobulin) and solutions avoiding gold colloidal cluster flocculation (eg, using protein G) were studied. CLISA was tested for other analytical purposes such as detection of IgEs in patients' sera.

A Highly Sensitive Immunochromatographic Strip Test for Rapid and Quantitative Detection of Saikosaponin d

“…The colloidal gold immunochromatographic assay (GICA) was developed in the 1980s to detect specific compounds in various types of samples in one step without other treatments using a cellulose membrane as the carrier [ 2 , 3 , 4 ]. Based on the specific binding of the antigen and antibody, the GICA is a sensitive method for the microanalysis of antigens and antibodies [ 5 , 6 ]. Membrane-based lateral-flow immunochromatographic strips (ICSs) are a useful tool for low-cost and rapid detection based on the GICA [ 7 , 8 , 9 ].…”