A Comparative Analysis of Methods for Titering Reovirus

Area of Science:

• Virology
• Cell Biology
• Biotechnology

Background:

• Accurate measurement of virus titers is crucial for understanding viral amplification and virulence.
• Traditional methods like the median tissue culture infectious dose (TCID50) are time-consuming and labor-intensive.
• There is a need for simpler, more convenient, and rapid methods for quantifying virus titers.

Purpose of the Study:

• To establish a standard curve correlating real-time unlabeled cell analysis (RTCA) half-cell index time (CIT50) with virus titer.
• To evaluate the feasibility and application value of RTCA and tunable resistance pulse detection (TRPS) technologies for virus titer measurement.
• To compare the performance of RTCA and TRPS against the traditional TCID50 method.

Main Methods:

• L929 cells were cultured to determine optimal inoculation density.
• RTCA was employed to analyze half-cell index (CI50) values of reovirus-infected L929 cells.
• A CIT50-TCID50 standard curve and regression equation were developed; RTCA, TCID50, and TRPS methods were used for reovirus titer detection.

Main Results:

• Optimal L929 cell propagation occurred at an initial density of 6 × 103 cells/well.
• A linear correlation (R2 = 0.9742) was found between CIT50 and TCID50: y = -2.1806x + 71.023.
• Virus titers obtained were 7×10^9.6821 pfu/mL (RTCA), 4.52×10^10 pfu/mL (TRPS), and 7×10^9.467 pfu/mL (TCID50).

Conclusions:

• The RTCA-based CIT50-TCID50 standard curve method provides a quantitative and rapid means for reovirus titer detection using L929 cells.
• RTCA offers high sensitivity and accuracy with reduced assay time compared to the TCID50 method.
• TRPS technology is faster for virus quantification but shows lower precision than RTCA and TCID50.