2 Materials
2.1 Infectivity Assay
Replacement
with Adherent
HEK-293 Cells (Initial
Titer)
1. Dulbecco’s phosphate buffered saline without calcium and
magnesium (DPBS; 1Â).
2. Cell dissociation reagent such as TrypLE™ or Accutase
® (see
Note 1).
3. Cell culture medium (see Note 2).
4. Viral stock of known titer (see Note 3).
5. LumaCyte Stabilization Fluid (LumaCyte SF1800).
6. Paraformaldehyde solution (optional—see Note 4): 4% in
0.1 M phosphate buffered saline, pH 7.4.
Fig. 1 Schematic outlining the experimental steps for each of the three laser force cytology assays described
in this study. The laser force cytology infectivity assay (1) measures the viral titer of a stock and serves as a
replacement for traditional methods such as the plaque assay or TCID50. The in-process laser force cytology
infectivity assay (2) provides the capability of analyzing cells with LFC from an ongoing process and
calculating the infectivity directly based on a known correlation. Finally, the laser force cytology neutralization
assay (3) can be used to measure the ability of serum or other agents to neutralize a virus, similar to the more
traditional plaque reduction neutralization test
Viral Infectivity Analysis Using Laser Force Cytology
577
2.1 Infectivity Assay
Replacement
with Adherent
HEK-293 Cells (Initial
Titer)
1. Dulbecco’s phosphate buffered saline without calcium and
magnesium (DPBS; 1Â).
2. Cell dissociation reagent such as TrypLE™ or Accutase
® (see
Note 1).
3. Cell culture medium (see Note 2).
4. Viral stock of known titer (see Note 3).
5. LumaCyte Stabilization Fluid (LumaCyte SF1800).
6. Paraformaldehyde solution (optional—see Note 4): 4% in
0.1 M phosphate buffered saline, pH 7.4.
Fig. 1 Schematic outlining the experimental steps for each of the three laser force cytology assays described
in this study. The laser force cytology infectivity assay (1) measures the viral titer of a stock and serves as a
replacement for traditional methods such as the plaque assay or TCID50. The in-process laser force cytology
infectivity assay (2) provides the capability of analyzing cells with LFC from an ongoing process and
calculating the infectivity directly based on a known correlation. Finally, the laser force cytology neutralization
assay (3) can be used to measure the ability of serum or other agents to neutralize a virus, similar to the more
traditional plaque reduction neutralization test
Viral Infectivity Analysis Using Laser Force Cytology
577