TCID50 Assay

Creative Biolabs has a highly skilled analytical team capable of performing a wide range of assays. To meet our customers' needs, we developed the Median Tissue Culture Infectious Dose (TCID50) assay to determine the viral titer of a testing virus. Our team will collaborate with you to identify and develop qualified assays to meet the needs of your specific project.

TCID50 Assay

The measurement of virus titer is one of the most important procedures in virology. Plaque assay is the most practical method and the gold standard for determining infectious viral titer. However, many viruses do not form traditional plaques, and tools for determining viral foci via immunolabeling or fluorescent reporters may not be readily available. The TCID50 assay is used to determine viral titers by determining the concentration at which 50% of infected cells exhibit cytopathic effect (CPE). Cell rounding, fusing, and other morphological changes are phenotypically indicative of CPE. This method is also used for viruses that are not cytopathogenic or do not form plaques. As a result, the TCID50 assay can be used to assess the infectious titer of any such virus.

Our TCID50 Assay Service

Creative Biolabs offers TCID50 assay services with high sensitivity and accuracy. Assays can be selected and tailored to your specific concerns and requirements, ensuring that an appropriate testing plan is developed for your project.

The TCID50 assay workflow is as follows:

  • Because not all virus types cause CPE in tissue culture, cell line and virus must be carefully matched to see a cytopathic effect.
  • On a well plate titer, host tissue cells are cultured, and then varying dilutions of the testing viral fluid are added to the wells.
  • Following incubation, the percentage of infected wells for each dilution is determined, and the results are used to calculate the TCID50 value.
  • Our TCID50 assays are performed in 96-well plates, with MTT uptake for cell death or immunofluorescence for infectivity as the readout.
  • TCID50 assay results can be analyzed using a variety of mathematical methods, including the Reed-Muench4, Spearman-Kärber, and Weil methods.

TCID50 assay workflow. (Creative Biolabs)Fig.1 TCID50 assay workflow. (Creative Biolabs)


  • Tailor-made virus titration/quantification assays
  • High sensitivity and accuracy
  • Professional data processing and analysis

Creative Biolabs provides an effective platform for viral research. Our TCID50 Assay services allow for the quick, simple, and accurate determination of infectious viral titer. Our laboratories can offer you customized solutions based on decades of industry experience, making us your preferred strategic partner. Please contact us if you require any additional information.


  1. Klimov, A.; et al, Influenza virus titration, antigenic characterization, and serological methods for antibody detection // Influenza Virus. Humana Press, 2012: 25-51.

All products and services are intended for Research Use Only, and NOT to be used in diagnostic or therapeutic procedures.

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