TCID50 Assay Services

TCID50 ASSAY SERVICE

Get Your TCID50 Assay Done Perfectly

The Tissue Culture Infectious Dose 50 (TCID50) is the dose of virus required to kill cells in 50% of infected wells. With this information, mathematical methods are then used to derive the amount of infectious virus in a sample or preparation. This technique allows for more rapid quantification of the virus infectious units present in a sample than is possible using the plaque/immunofocus assay. The TCID50 method can also be used as an initial test, using those cell types intended for use in further assays, thus providing a good estimate of the amount of virus required to obtain a given percentage of infection.

 

Our Approach

How our TCID50 assays are done.

How we do it
In a traditional TCID50 assay, a serial dilution of the test sample is incubated with permissive cells (or any cell line of interest) for enough time to generate quantifiable cell death, also known as cytopathic effect (CPE). Each dilution is tested in at least four wells. When CPE is clearly visible in all infected wells, cells are fixed and stained with crystal violet. Uninfected wells will stain violet, and infected wells will not stain, providing a binary reading that allows us to measure the TCID50.

When the virus is not strongly cytopathic or when an earlier readout is required, cells can be immunostained for a viral antigen, and the percentage of infection is determined by immunofluorescence.

What is it used for?
At VRS, we use the TCID50 assays to:
• titrate infectious virus in viral stocks
• as a readout for our virucidal tests (e.g., ISO21702, ISO18184, suspension tests)
• quantify infectious virus in cell culture media, blood, or tissue samples
• determine the dose of virus required to obtain a certain percentage of infection/cytotoxicity in a cell line of interest for downstream assays
• study virus release

TCID50 testing is readily available for the following viruses:
SARS-CoV-2
Human coronaviruses NL63, 229E, and OC43
Influenza virus
Respiratory syncytial virus (RSV)
Enterovirus D68
Adenovirus
Rhinovirus
Murine norovirus
Human cytomegalovirus (HCMV)
Vaccinia virus
Semliki Forest virus
Ross River virus
Sindbis virus

Other viruses may be available on request.

If TCID50 testing can be useful for you, get in touch and one of our scientists will get back to you.

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