Enhanced detection of respiratory viruses using cryopreserved R-Mix ReadyCells

Jang Su Kim, Sun Hyung Kim, Sook Young Bae, Chae Seung Lim, Young Kee Kim, Kap No Lee, Chang Kyu Lee

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


Background: R-Mix, which contains a fresh mixture of two cell lines, Mv1Lu (mink lung cells) and A549 cells, has shown good sensitivity and specificity for respiratory virus culture. However, it has until recently only been available in North America, in part due to the shipping constraints associated with cell aging and the difficulty in providing these cells to hard to reach regions. Recently, cryopreserved R-Mix ReadyCells for longer storage were developed. These cells, which are shipped on dry ice and have a shelf life as long as 6 months from date of manufacture, can be thawed and used as needed with minimal addition of refeeding media. Objective: Assess the potential for cryopreserved R-Mix ReadyCells to replace conventional culture. Study design: Two hundred and twenty-three nasopharyngeal aspirates confirmed as respiratory virus-positive by conventional culture were inoculated into cryopreserved R-Mix ReadyCells and re-inoculated into conventional culture cells simultaneously. After 1 and 3 days of incubation cryopreserved R-Mix ReadyCells and conventional culture cells were screened using a respiratory virus fluorescent antibody pool for the detection of seven major respiratory viruses (influenza A and B viruses, parainfluenza 1, 2 and 3 viruses, respiratory syncytial virus and adenovirus). Positive pool results were further differentiated with specific monoclonal antibodies against the individual viruses. Results: After 1 day of incubation detection rates for conventional culture were 25%, 39%, 39%, 49%, and 10% for influenza A virus, influenza B virus, parainfluenza viruses, respiratory syncytial virus, and adenovirus, respectively. Corresponding detection rates for cryopreserved R-Mix ReadyCells were 78%, 91%, 72%, 81%, and 65%. Average detection rates of cryopreserved R-Mix ReadyCells for all respiratory viruses were 80% after 1 day incubation and 95% after 3 days incubation, compared to 35% and 70% by conventional culture. Conclusion: The cryopreserved R-Mix ReadyCells system offers a highly sensitive and rapid method for detection of respiratory viruses that may allow it to replace conventional cell culture systems.

Original languageEnglish
Pages (from-to)264-267
Number of pages4
JournalJournal of Clinical Virology
Issue number3
Publication statusPublished - 2008 Jul


  • Conventional culture
  • Cryopreserved R-Mix ReadyCells
  • Respiratory virus

ASJC Scopus subject areas

  • Virology
  • Infectious Diseases


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