As IgM does not cross the blood-brain barrier, IgM antibody in CSF strongly suggests central nervous system infection. Polymerase chain reaction (PCR) can also be performed on the CSF. Those who ...

Since its first appearance in the US in 1999, West Nile ... antibody to detect antigen (or serum antibody in the case of IgG enzyme immunoassay); the enzyme catalyzes a color reaction when exposed ...