BLAST is an online sequence alignment tool by NCBI.

I am sequencing the genome of the Dengue virus itself that we extract from an infected person. And we are able to determine the serotype affecting a person via real time PCR itself. So we draw the patient's blood, spin it down into serums, then we do nucleic acid extraction to obtain the RNA. Then we do real time RT-PCR to detect the presence of any sereotype of the virus.