Comparison of the Plaque Assay and 50% Cell Culture Infectious Dose Assay Methods for Quantification Measuring SARS-CoV-2 Wuhan-Hu-1 Strain Infectivity

Main Article Content

Sakalin Trisiriwanich
Sompong Sapsutthipas
Kornnika Kullabutr
Ashma Yuso
Supaporn Phumiamorn

Abstract

Background: The Corona Virus Disease 2019 (COVID-19), which causes from the Severe Acute Respiratory Syndrome Corona Virus (SAR-CoV-2), is an emerging disease that several organizations have tried to develop vaccines against the viruses and therapeutic medicines, including specific anti-viral drugs. Therefore, viral cultivation and quantification are necessary for the laboratory testing. Most of common methods to quantify the viral titer are the Plaque and CCID50 assays.


Objective: To compare the quantity of the SAR-CoV-2 and the consumption resources test between the plaque and CCID50 assays (original strain).


Method: This study was an experimental research from March to June 2020 by comparing the quantification of the SAR-CoV-2 between both methods using the same virus set at 80 tests in the same period.


Result: The results showed that the geometric means of viral titers determined by the plaque and CCID50 assays were 5.97 log PFU/ml and 6.00 log CCID50/ml, respectively. The percentages of the coefficient of variance of the methods were 4.09 and 3.29, respectively. The statistical analysis by the Paired-t test showed no statistically significant difference between these two methods at a 95% confidence interval. In addition, the ratio of viral titers of the mean over the geometric mean ranged between 0.87 and 1.13. However, the CCID50 assay was faster by requiring only 4 days of testing and more cost-effective by using fewer materials, equipment, and medium.


Conclusion: The determination of SARS-CoV-2 virus counting by the plague counting method and the 50% cell culture infection test showed no difference in results, but testing for 50% infection in cell cultures was faster and more cost-effective. It revealed that both methods can be used to quantify the SARS-CoV-2 titer, which can be applied to detect immune responses in COVID-19 patients as well as in COVID-19 vaccine testing further in animals and humans.

Article Details

How to Cite
1.
Trisiriwanich S, Sapsutthipas S, Kullabutr K, Yuso A, Phumiamorn S. Comparison of the Plaque Assay and 50% Cell Culture Infectious Dose Assay Methods for Quantification Measuring SARS-CoV-2 Wuhan-Hu-1 Strain Infectivity. Thai Food and Drug J [Internet]. 2023 Aug. 3 [cited 2024 Oct. 8];30(2):33-48. Available from: https://he01.tci-thaijo.org/index.php/fdajournal/article/view/265170
Section
Research Article

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