One of the most serious health problems is dengue infection, which known to be endemic in tropical and subtropical countries, including Indonesia. Over the past five decades, the number of dengue cases has increased exponentially every year with average 1 % of case fatality rate (CFR) in Indonesia. However, the CFR due to dengue infection can be reduced through early detection of patients by utilizing the role of antibodies. This preliminary study was conducted to clone recombinant Fab that can specifically detect NS1 dengue virus. Using hybridoma cell line A6, secreting anti-dengue NS1, induced by Saccharomyces cerevisiae as a source of cDNA, the heavy chain of the Fab fragment was amplified by Polymerase Chain Reaction (PCR) technology. The amplified heavy chain gene then was inserted into the pTA2 vector by TA cloning method and transformed into Escherichia coli TOP10. The resulting clones were confirmed by PCR, single digestion with EcoRI restriction enzyme and sequencing. The results showed that the heavy chain gene sized ∼450 bp was successfully cloned into the pTA2 vector. Further study should be conducted to evaluate the expression of the recombinant Fab as a valuable material in the development of dengue diagnostic kit.