Feasibility of using 454 pyrosequencing for studying quasispecies of the whole dengue viral genome nork Chin-inmanu Kwanrutai, Suttitheptumrong Aroonroong, Sangsrakru Duangjai, Tangphatsornruang Sithichoke, Tragoonrung Somvong, Malasit Prida, Tungpradabkul Sumalee, Suriyaphol Prapat