This video demonstrates the imaging-based micro-neutralization assay to analyze the antigenic relations between influenza A and B viruses. It provides a quantitative and visual way to assess the effectiveness of antibodies or other treatments in preventing viral infection.
Protocol
1. Virus Titration NOTE: Depending on the number of viruses and the number of duplicates, a well plate can be set up with the following flexibilities: (1) The viral dilution can be arranged along either the rows or the columns (Figure 1). Each virus should occupy a separate row/column. (2) The viral dilution increment is flexible, but it should start with the highest viral concentration at the top-left corner. (3) There is no restriction on the …
Representative Results
Figure 1: Example of a well-plate setup in a virus titration experiment. Test viruses are assigned to separate rows (A to H). Columns are designed for different viral dilutions (1 to 12). Two columns were used as duplicates for each viral dilution. Scale bar = 10 mm. …
Disclosures
The authors have nothing to disclose.
Materials
VGM
Sigma
D6429, P0781
500 ml DMEM+5 ml Pen/Strepb
PBS A
Nature pH Phosphate-buffered saline: NaCl 10 g, KCl 0.25 g, Na2HPO4 1.437 g, KH2PO4 0.25 g, and Dist. Water 1 L
Avicell
FMC
RC-581F
2.4 g in 100 ml distilled water dissolved by agitation on a magnetic stirrer for 1 hr. Sterilize by autoclaving
2x DMEM
Gibco
21935-028
Trypsin
Sigma
T1426
Overlay (10 ml/plate):
5 ml 2x DMEM, Trypsin 2 μg/ml final concentration, Avicell 5 ml
Triton X- 100 e
Sigma
T8787
Permeabilization buffer: 0.2% in PBS A (v/v)
Tween 80
Sigma
P5188
Wash Buffer: 0.05% Tween 80 in PBS A (v/v)
Horse serum
PAA Labs Ltd
B15-021
ELISA Buffer: 10% in PBS A (v/v) + 0.1% Tween 80
Mouse MAb against influenza type A
Biorad
MCA 400
1 st Antibody: 1:1,000 in ELISA Buffer
Goat anti-mouse IgG (H+L) HRP conjugate
Biorad
172-1011
2 nd Antibody: 1:1,000 in ELISA Buffer
True Blu peroxidase substrate
KPL
50-78-02
Substrate: True blue +0.03% H2O2 g (1:1,000 of 30% solution)
96-well flat-bottom microtitre plates
Costar
3596
8 channel multiwall-plate washer and manifold
Sigma
M2656
Perfection Plate Scanner
Epson
V750 Pro
The imaging software can be downloaded freely from http://www.epson.com/cgi-bin/ Store/support/supDetail.jsp? oid=66134&infoType=Downloads.
Analyzing the Antigenic Relationship between Viruses using an Image-Based Microneutralization Assay. J. Vis. Exp. (Pending Publication), e21924, doi: (2024).