Real-time cell analysis – A new method for dynamic, quantitative measurement of infectious viruses and antiserum neutralizing activity

• Published in: Journal of virological methods 2013-11, Vol.193 (2), p.364-370
• Main Authors: Teng, Zheng, Kuang, Xiaozhou, Wang, Jiayu, Zhang, Xi
• Format: Article
• Language: English
• Subjects: animals; antibodies; Antibodies, Neutralizing - blood; Antibodies, Viral - blood; antiserum; Cell Line; Cytological Techniques - methods; Cytopathogenic Effect, Viral; cytopathogenicity; death; Enterovirus A, Human - growth & development; Enterovirus A, Human - isolation & purification; HEV71; human diseases; Human enterovirus; Humans; model validation; monitoring; neutralization; neutralization tests; Neutralization Tests - methods; quantitative analysis; RCTA; sowing; TCID50; tissue culture; vertebrate viruses; Viral assay; viral load; Viral Load - methods; Virology - methods; viruses
• ISSN: 0166-0934; 1879-0984
• DOI: 10.1016/j.jviromet.2013.06.034

•We report a novel alternative viral assay to measure viral infectivity.•RTCA system can be used for quantitative measurement of infectious viruses.•RTCA is able to measure viral infection and anti-viral serum titer in real time.•RTCA system has the potential for the quantification of other pathogenic viruses. A newly developed electronic cell sensor array – the xCELLigence real-time cell analysis (RTCA) system is tested currently for dynamic monitoring of cell attachment, proliferation, damage, and death. In this study, human enterovirus (HEV71) infection of human rhabdomyosarcoma (RD) was used as an in vitro model to validate the application of this novel system as a straightforward and efficient assay for quantitative measurement of infectious viruses based on virus-induced cytopathic effect (CPE). Several experimental tests were performed including the determination of optimal seeding density of the RD cells in 96-well E-plates, RTCA real-time monitoring of the virus induced CPE and virus titer calculation, and viral neutralization test to determine HEV71 antibody titer. Traditional 50% tissue culture infective dose (TCID50) assay was also conducted for methodology comparison and validation, which indicated a consistent result between the two assays. These findings indicate that the xCELLigence RTCA system can be a valuable addition to current viral assays for quantitative measurement of infectious viruses and quantitation of neutralization antibody titer in real-time, warranting for future research and exploration of applications to many other animal and human viruses.