Method Description

Dengue virus IgM:

In this enzyme-linked immunosorbent assay (ELISA), samples and controls are diluted in sample dilution buffer and incubated in microtiter wells coated with antihuman IgM antibodies. This incubation is followed by incubation with dengue-derived recombinant antigens (DENRA) and normal cell antigen (NCA) separately. After incubation and washing, the wells are treated with a DEN-specific monoclonal antibody labeled with horseradish peroxidase (HRP). After a second incubation and washing step, the wells are incubated with tetramethylbenzidine (TMB) substrate. Acid stop is added and absorbance at 450 nm is read. The ratio of absorbencies of the DENRA and the control antigen wells determine whether the result is positive or negative.(Package insert: InBiOS DENV Detect IgM CAPTURE ELISA. InBios International, Inc; Revision 10/01/2019)

Dengue virus IgG:

In this ELISA assay, controls and diluted samples are incubated in microtiter wells coated with monoclonal antibody bound to DENRA. After incubation and washing, wells are treated with IgG antibody labeled with HRP. After a second incubation and washing, wells are incubated with TMB substrate. Acid stop is added and absorbance at 450 nm is measured. The ratio of the absorbencies of the DENRA and the control wells determines whether a result is positive or negative.(Unpublished Mayo method)

Nonstructural protein 1:

The InBios nonstructural protein 1 (NS1) ELISA is a 2-step sandwich-format colorimetric immunoassay for qualitative detection of NS1 antigen in serum. Diluted patient samples and controls are incubated in wells coated with purified capture antibody, specific for the dengue NS1 antigen. Following incubation, wells are washed, incubated with HRP-conjugated polyclonal antibody specific to NS1 antigen and reincubated. Wells are subsequently washed and TMB substrate is added and incubated at room temperature in the dark. Stop solution is added next and the optical density (OD) of the reaction is measured at 450/620 nm. The immune status ratio for each sample is calculated from the ratio of the OD obtained with the test sample divided by the OD from the calculated cutoff value (determined by the cutoff control sample).(Package insert: InBios DENV Detect NS1 ELISA.InBios International, Inc; Revision 01/18/2019)