en تخصصي Special پژوهشي Original article <div><strong>Background and Aims:</strong> Infectious bronchitis (IB) is one of the significant economically critical poultry diseases distributed worldwide, including Iran. Different IB virus (IBV) genotypes are circulating in different geographical regions. Typing of IBV strains is useful for implementation of control measures and for understanding the epidemiology and evolution of IBV. The S1 gene sequencing is used for IBV genotyping. Massachusetts, 793/B, QX, and IS-14194 IBV genotypes currently exist in Iranian poultry farms. This study aims to design an RFLP-based method to do genotyping and confirm of mentioned IBV genotypes.<br> <strong>Materials and Methods:</strong> After amplification of parts of the S1 gene (RT-PCR), the PCR products treated with four enzymes (SfoI: Massachusetts, BtsCI: 793/B, MspI: IS-1494, and NruI: QX) and finally visualized on agarose gel electrophoresis.<br> <strong>Results:</strong> Results showed 100 percent of the specificity of the newly designed method (in comparison with sequencing).<br> <strong>Conclusions: </strong>This method can be used for primary confirmation and fast screening of Massachusetts, 793/B, QX, and IS-14194 IBV genotypes and even in local laboratories without the need for sequencing.</div> Avian Infectious Bronchitis, Iran, RFLP, Genotyping 19 24 http://journal.isv.org.ir/browse.php?a_code=A-10-120-9&slc_lang=en&sid=1 Vahid Karimi Vkarimi@ut.ac.ir 10031947532846006962 10031947532846006962 No Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Arash Ghalyanchilangeroudi Arashghalyanchi@gmail.com 10031947532846006963 10031947532846006963 Yes Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Fatemeh Gholami jalalg77@yahoo.com 10031947532846006964 10031947532846006964 No Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Masoud Hasehmzadeh hashemzadehma@gmail.com 10031947532846006965 10031947532846006965 No RAZI Institute, Karaj, Iran AmirHossein Mohseni amirhossein_mohseni@hotmail.com 10031947532846006966 10031947532846006966 No Department of Microbiology, Faculty of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran Hossein Hosseini hosseini.ho@gmail.com 10031947532846006967 10031947532846006967 No Department of Clinical Sciences, Faculty of Veterinary Medicine, Islamic Azad University, Karaj Branch, Alborz, Iran Naser Sadri naser.sadri@ymail.com 10031947532846006968 10031947532846006968 No Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Amir Modiri Hamdan 10031947532846006969 10031947532846006969 No Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran