The isolated ns1 gene was high identity with Dengue virus 1 polyprotein-like gene (gene ID: ). The ns1 gene was successfully inserted into the expression vector pET22b(+) in an open reading frame. The successful expression of recombinant NS1 protein (rNS1) in E. coli BL21 (DE3) was checked by SDS-PAGE and confirmed by Western blot. Some suitable conditions for high expression of rNS1 protein were mM IPTG, 4 hours induction and initial inoculum density of . | Journal of Science & Technology 126 (2018) 038-043 Cloning and Expression of the Dengue virus Non-structural Protein 1 (NS1) in E. coli Truong Quoc Phong*, Chu Thi Minh Hai, Le Van Hoang, Dang Thi Huyen Trang Hanoi University of Science and Technology – No. 1, Dai Co Viet Str., Hai Ba Trung, Ha Noi, Viet Nam Received: July 26, 2017; Accepted: June 25, 2018 Abstract Dengue is an infectious disease that poses a threat to approximately billion people in 128 countries in the world. A report in 2013 indicates average of 390 million dengue infections per year. Non-structural protein 1 (NS1) is a highly conversed dengue virus glycoprotein and considered as a specific biomarker for serodiagnosis of dengue infection. In the present study, the ns1 gene encoding the non-structural protein 1 (NS1) from the Vietnam Dengue virus isolate was cloned and sequenced. The isolated ns1 gene was high identity with Dengue virus 1 polyprotein-like gene (gene ID: ). The ns1 gene was successfully inserted into the expression vector pET22b(+) in an open reading frame. The successful expression of recombinant NS1 protein (rNS1) in E. coli BL21 (DE3) was checked by SDS-PAGE and confirmed by Western blot. Some suitable conditions for high expression of rNS1 protein were mM IPTG, 4 hours induction and initial inoculum density of . Keywords: Dengue virus, E. coli, non-structural protein (NS1), recombinant 1. Introduction the current antibody test in case dengue antibodies are still undetectable [4]. * Dengue virus is one of the most dangerous viruses, posing a threat to one-third of the global human population in tropical and sub-tropical regions. Dengue virus is the cause of Dengue Fever, Dengue Hemorrhagic Fever (DHF) and most seriously Dengue shock syndrome (DSS) [1]. Dengue is caused by one to four dengue serotypes (DENV14). In Vietnam, DENV1 is the highest prevalence among four serotypes. Dengue is a single, positivesense, RNA virus with a genome of approximately .