Rapid identification of dengue virus serotypes by using polymerase chain reaction.

Four primer pairs were selected on the basis of the published sequence data of four dengue virus serotypes so that each unique target sequence size could be amplified for each serotype by polymerase chain reaction. The procedure consists of (i) RNA preparation, (ii) reverse transcription, and (iii) polymerase chain reaction, all of which could be completed within 2 h in a single tube for each specimen. The amplified sequence size revealed by ethidium bromide-stained agarose gel electrophoresis was unique for each serotype, using infected culture fluid of isolates from dengue fever or dengue hemorrhagic fever patients in Thailand, Indonesia, and the Philippines as well as from prototype viruses, thus facilitating simultaneous identification and typing.