TABLE 1.

Specificity and sensitivity of serotype-specific and group-specific NS1 antigen capture ELISAs for detection of NS1 in serially diluted viral culture supernatants from each virus serotype quantified by plaque assay

VirusViral titer (PFU/ml)P/N ratioa by serotype-specific NS1 ELISAGroup-specific NS1 ELISA resultbPanbio NS1 ELISA resultc
DENV1DENV2DENV3DENV4
DENV112,50056.646.6103.0
6,25067.772.297.9
3,12561.670.092.5
1,56361.766.473.4
78255.741.753.2
39142.517.331.4
19628.39.816.7
9815.95.4
497.23.0
254.32.2
12.52.3
6.25
DENV212,50078.469.893.4
6,25084.969.083.3
3,12580.646.263.3
1,56354.921.841.1
78227.811.023.9
39115.65.811.6
1968.83.2
985.02.5
493.1
25
DENV312,50049.071.453.3
6,25034.156.632.0
3,12519.438.217.9
1,56310.121.39.7d
7825.810.6
3913.76.0
1962.43.6
982.9
49
DENV4100,00046.023.317.6
50,00037.713.59.7d
25,00026.813.8
12,50012.48.0
6,2507.14.6
3,1253.62.9
1,5632.2
782
  • a P/N ratio, OD450 of test infected culture/OD450 of test uninfected control culture.

  • b Results of group-specific ELISA are indicated by the P/N ratio. Test samples were considered positive if their mean absorbance was greater than twice the mean absorbance of the controls.

  • c Panbio NS1 ELISA; the results are given as Panbio units; results of <9, 9 to 11, and >11 were defined as negative (−), equivocal (±), and positive (+) for detection of NS1, respectively, according to the manufacturer's instructions.

  • d Equivocal results (interpreted according to the Panbio assay manual). The experiment was repeated twice with similar results.