Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 1 2015 02 15 105 112 EN Saeid Goudarzi Clinical Nanomedicine Laboratory, ENT- Head & Neck Research Center, Hazrate Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran Anita Ahmadi Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran AND Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Research Institute, Tehran University of Medical Sciences, Tehran, Iran Mohammad Farhadi Clinical Nanomedicine Laboratory, ENT- Head & Neck Research Center, Hazrate Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran Seyed Kamran Kamrava Clinical Nanomedicine Laboratory, ENT- Head & Neck Research Center, Hazrate Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran Shiva Saghafi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran Kobra Omidfar Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran AND Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Research Institute, Tehran University of Medical Sciences, Tehran, Iran 2015 10 16 A new competitive immunochromatography (ICG) strip test based on polyclonal antibody (pAb) conjugated with gold nanoparticles (NPs) was developed and its applications for primary screening of immunoglobulin (Ig) A in serum were evaluated. Nanocolloidal gold as the detection reagent, with an average particle diameter of 20 nm, was synthesized and labelled pAb. The antibody-nanocolloidal gold probe was applied on the conjugate pad, and human IgA was immobilized on a nitrocellulose membrane as the capture reagent to prepare the ICG strip test. It took only 10 minutes to accomplish a semi-quantitative detection of serum IgA in this assay. In the optimized investigational conditions, the ICG strip test could distinguish human serum IgA in the range from 1 to 270 ng/mL with a detection limit of 5 ng/mL. The reliability of testing procedures was examined by performing the ICG strip test with 11 serum samples and comparing the results with those obtained via enzyme-linked immunosorbent assay (ELISA). The ICG strip was sufficiently sensitive and accurate for a rapid screening of IgA in human serum. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/405 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/405/432