Nirmidas pGOLD (plasmonic gold) Serology Assays for the Diagnosis of Zika and Dengue

For research use only

Zika/Dengue Assay Kit Example

Zika/Dengue Assay Kit Example

Nirmidas Biotech Inc. announces the availability of three pGOLD-Zika/Dengue IgG/IgM/IgA Assay kits for rapid, simultaneous, multiplexed detection of IgG, IgM and IgA antibodies against Zika virus (ZIKV) and Dengue virus (DENV), each requiring only 1 micro-liter of patient sera. A unique IgG avidity test against both ZIKV and DENV is also developed. These assays, published in the March 6 issue of Nature Medicine can facilitate differentiating ZIKV from DENV infection, and revealing whether the infection occurred recently (low avidity) or in the past (high avidity) for both Zika and Dengue infections.

The current Zika diagnostic tests are non-ideal due to narrow diagnostic window (RNA detection by PCR), cross reactivity (Zika IgM test) or time-consuming and laborious procedures (plaque reduction neutralization testing, PRNT). The simultaneous ZIKV and DENV IgG/IgA testing, enabled by the pGOLD assay, is novel with an important finding that the cross-reactivity problem between ZIKV and DENV IgG and IgA antibodies occurs at a much lower degree than IgM antibodies, thus allowing highly specific diagnosis of ZIKV infection and differentiation from Dengue infection. ZIKV IgA positivity is found to be highly specific to early stage ZIKV infection. For a ZIKV infected cohort with symptom onset to sample collection time of 2-90 days in the acute-convalescent phase, the pGOLD IgG/IgA test can diagnose ZIKV infection with > 90% sensitivity and ~ 98% specificity, with little cross-reactivity problem due to chronic or on-going DENV infection. For an acute-phase ZIKV infected (< 6 days after symptom onset, positive by PCR test) cohort from the Dominican Republic, the pGOLD IgG/IgA assay can still detect ~ 47% of the ZIKV infection.

Assay Kits Available:

1. Simultaneous Zika/Dengue IgG IgA test against ZIKV NS1 and DENV viral antigens

  •  Uses low sample volume of ~ 1 µl
  • ~ 2-hour processing time for results
  •  IgG and IgA are reported by two different colors of fluorescence.

2. Simultaneous Zika/Dengue IgG IgM test against ZIKV NS1 and DENV viral antigens

  •  Uses low sample volume of ~ 1 µl
  •  ~ 2-hour processing time for results
  • IgG and IgM are reported by two different colors of fluorescence.

3. Zika/Dengue IgG avidity

  • Uses low sample volume of ~ 1 µl
  • ~ 2-hour processing time for results
  • IgG is reported by 800 nm NIR fluorescence. Each sample will be tested with and without urea treatment.

Format of assays:

ELISA-like assay plate consisting of 4 pGOLD slides

ELISA-like assay plate consisting of 4 pGOLD slides

pGOLD assay is in a format similar to multi-well microplates widely used in ELISA and can be considered as multiplexed ELISA with very similar assay procedures. Automated washers are readily available and can also be processed manually. Plate reading can be done by MidaScan reader offered by Nirmidas for best results or use existing fluorescence readers.

How the tests can be used:

  • Perform ZIKV/DENV IgG and IgM antibody test; and ZIKV and DENV IgG avidity test.
    • Avidity test can identify if the patient had prior ZIKV or DENV infection.
    • For primary infection without prior flaviviral infection, ZIKV IgG/IgM test can detect ZIKV infection in acute, convalescent and chronic phases. 
  • Perform ZIKV/DENV IgG and IgA antibody test; and ZIKV and DENV IgG avidity test.
    • Avidity test can identify if the patient had prior ZIKV or DENV infection.
    • For patients with prior DENV infection as is the case for adults in dengue endemic regions, ZIKV infection would be considered as secondary infection. ZIKV IgG/IgA test can detect ZIKV infection in acute, convalescent and chronic phase.  Secondary DENV infection can also be detected by pGOLD IgG/IgM and avidity test.

Multiplexed assay kit for a panel of flaviviral and alphaviral infections:

Nirmidas is developing a multiplexed IgG/IgM and IgG/IgA as well as IgG avidity test for ZIKV, DENV, JEV, YFV, WNV, CHIV, BEV and USUTU. The assay will require only 1 micro-liter of serum or whole blood for simultaneous detection of all major flaviviral and alphaviral infections.

Customized assay:

Nirmidas is open to collaborations on customized assays on the pGOLD platform, with any antigens provided by the customers in single-plex or multiplexed formats for diagnosis of infectious and other diseases.

Testing service:

Nirmidas provides testing service for flaviviral infections at a highly affordable price. 

Contact:

For purchase of kits, customized assay and assay service, email us at sales@nirmidas.com

Research Use Only

We will contact you if you inquire here to learn more about pGOLD-Zika/Dengue IgG/IgM/IgA and IgG Avidity Assay Kits:

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