Cell culture and virus

C6/36 cells (ATCC: CRL-1660) were cultured in Leibovitz’s L-15 medium (Gibco, 41300039) supplemented with 10% Fetal Bovine Serum (FBS, Gibco, 10270) and 10% Tryptose Phosphate Broth (TPB) solution (Sigma, T9157). The C6/36 cells were grown at 25°C without CO₂. BHK-21 cells (ATCC: CCL-10) were used for virus titration. BHK-21 cells were cultured in Dulbecco’s modified Eagles Medium (DMEM, Gibco, 11995065) supplemented with 10% FBS (Gibco, 10270) at 37°C and 5% CO₂. In this study, DENV serotype 1 (DENV-1) of Hawaiian strain, and ZIKV of strain H/PF/2013 were used. Both viruses were propagated in C6/36 cells. Virus titer of DENV and ZIKV was determined using tissue culture infectious dose 50 (TCID50) assay. DENV-1 (Hawaiian strain) was a gift from David Perera, University Malaysia Sarawak, and ZIKV (H/PF/2013 strain) was a gift from Shee Mei Lok, Duke-NUS Medical School, Singapore.