An Assay to Measure Influenza Neuraminidase Inhibition Antibody Titers
Abstract
Source: Gao, J., et al. Measuring Influenza Neuraminidase Inhibition Antibody Titers by Enzyme-linked Lectin Assay. J. Vis. Exp. (2016).
This video demonstrates an assay measuring influenza neuraminidase (NA) inhibiting antibody titers in a serum sample. A serum sample containing antibodies against NA is added to a fetuin-coated microwell plate. Upon adding the virus, the antibodies prevent viral NA from cleaving fetuin and exposing its galactose moiety. A peroxidase-conjugated lectin is then added, which binds to the exposed galactose. The NA-inhibiting antibody titer is determined using a colorimetric test, where a peroxidase substrate gets cleaved by the immobilized lectin-conjugated peroxidase to produce color.
Protocol
Representative Results
Divulgations
The authors have nothing to disclose.
Materials
| Coating buffer | KPL | 50-84-01 | |
| Fetuin | Sigma | F3385 | |
| 5X MES, pH 6.5 | KD-Medical | PBS-0134 | |
| CaCl2 | Sigma | C7902 | |
| 30% BSA | Sigma | A8327 | |
| Tween 20 | Sigma | P1379 | |
| Lectin PNA-HRPO | Sigma | L7759 | |
| PBS-T | Sigma | P3563-10PAK | |
| o-Phenylenediamine dihydrochloride | Sigma | P8287 | |
| Phosphate-citrate buffer | Sigma | P4922 | |
| Sulfuric acid | Sigma | 258105 | |
| 96-well Maxisorp plates | NUNC | 439454 | |
| 96-well round bottom well plates | NUNC | 267245 | |
| Plate sealers | Thermo Scientific | 14-245-192B | |
| Chicken eggs | Charles River Laboratories | 9 day old embryonated specific pathogen free (SPF) chicken eggs | |
| Multichannel pipette | Variety of suppliers e.g., Rainin, Eppendorf | 8 or 12 channel manual pipettem 50-250 µl volume | |
| Pipette tips | Depends on pipettor brand | Depends on pipettor brand | |
| Plate reader, with 490 nm filter | Perkin Elmer | Victor V | |
| Water bath set to 37 °C | Variety of suppliers | Variety of models | |
| Water bath set to 56 °C | Variety of suppliers | Variety of models | |
| Refrigerator set to 4 °C | Variety of suppliers | Variety of models | |
| Incubator set to 37 °C | Variety of suppliers | Variety of models |
