For sensitivity assessment, plasmids containing the target region of the 3'-NCR gene were constructed for each serotype for use in the LAMP reaction.The target DNA sequence was amplified
with 2 LAMP primers (F3 and B3 primers) by PCR and was then cloned into the pGEM-T cloning
vector (Promega, USA). Plasmid DNA purification was performed with a QIAprep Miniprep
kit (QIAGEN, Hilden, Germany). The resulting sequences were aligned using the 3'-NCR gene
sequences for DENV1-4 in GenBank to confirm that the target sequences were correct.