Viral Titers Determination Using TCID50

Viral titer is an important component of product development, manufacturing, and quality control for protein therapeutics such as recombinant proteins and viral vaccines. These vaccines use viral vectors as a means of cell entry or propagation. The TCID 50 (50% tissue culture infectious dose) assay is a common method for quantifying viral titer. CD Formulation has a highly skilled analytical team that can perform high-quality TCID 50 assay services to support developing and manufacturing your specific biologic product.

What is TCID50?

TCID 50 (50% tissue culture infectious dose) is an endpoint dilution assay used to measure infectious virus titers. TCID 50 represents the concentration at which 50% of the cells are infected when cultured cells are inoculated into a diluted viral solution in a test tube or well plate. This procedure quantifies viral titer by determining the concentration at which 50% of infected cells exhibit a cytopathic effect (CPE) and can be used to determine the infectious titer of any virus that can cause cytopathic effects in tissue culture. These viruses can produce CPE in tissue culture within 5 to 20 days while the cells in culture remain viable. It is important to note that not all viruses can cause CPE in tissue culture. The cell line and virus should be compared for CPE to be seen.

Our Services Related to TCID50 Assay

Thanks to decades of experience supporting biopharmaceutical product development and manufacturing using the TCID50 assay, CD Formulation is able to collaborate on your viral clearance research, as well as viral vaccine and recombinant protein product development projects, including product manufacturing and quality control, to ensure your biotherapeutic products successfully enter clinical stages and market.

Here, we offer TCID50 assay as a standalone service or as part of our other biotech services. We have an experienced team of experts who can provide you with high-quality technical support and leading virus removal research solutions, including but not limited to:

• Transfer, implementation and application of existing TCID50 assays.
• Transfer, implementation and application of existing plaque formation detection methods.
• Development of custom viral titration/quantification assays.

Our Workflow for TCID 50 Assay

Our TCID 50 assay procedure works by adding serial dilutions of the virus sample to cells in a 96-well plate. The cell type is specifically chosen to show a cytopathic effect (CPE). The calculation of the TCID50 for the virus sample is done by a variety of mathematical methods, such as the Muench-Reed method, the Spearman-Karber method, and the Weil method. Virus titers are expressed as TCID 50 /ml. Alternatively, automated fluorescence imaging and fluorescently labeled virus particles or fluorescent cell viability markers can be used to determine viral infection.

Specific workflow:

• Host tissue cell culture is performed in a 96-well plate. The cell type and culture density are determined based on the virus.
• Prepare serial dilutions of the virus. Make a 1:10 serial dilution of the original virus sample, and then add different dilutions of the test virus solution to the wells.
• After incubation, determine the percentage of infected wells for each dilution. Cell viability (MTT absorbance) assay as a readout to detect cell death, or immunofluorescence as a readout to detect infectivity. This can improve the sensitivity of the assay.
• Calculate TCID 50 using the Muench-Reed method, Spearman-Karber method, and Weil method.

Fig. 1 Workflow for viral titers determination using CID50 assay. (CD Formulation)

Advantages of Our TCID50 Assay

• Support viral clearance studies of your biologics as an complementary to qPCR technology.
• High sensitivity, allowing detection of low levels of viral infection, particularly suitable for studying viruses present in small quantities.
• Suitable for viruses that cannot be quantified by plaque assays.
• Less error compared to plaque assays.
• Very little information about the virus itself is required.
• High accuracy.

Custom TCID50 Assay Services

Why Choose Our TCID50 Assay?

• We have a team of experts with rich experience in TCID50 assay analytical method development and validation.
• We have accumulated decades of expertise and successful project experience using TCID50 assay technology to support protein/peptide biopharmaceutical development.
• Our team of experienced professionals has extensive knowledge in performing TCID50 tests, ensuring high accuracy and reliability of results.
• We value our partnership with our customers and are committed to providing continuous support and guidance during the project to ensure that your plan is implemented smoothly.
• We offer flexible experimental design and testing options to meet the specific needs of any customer.

Publication

CD Formulation aims to provide a powerful analytical tool for viral titer determination in protein and peptide biopharmaceutical development and manufacturing. Please feel free to contact us if you are interested in our services. Learn how our TCID50 assay technology can support the smooth implementation of your protein/peptide biopharmaceutical program.

How It Works

STEP 1

Submit a service request describing your specific research or development need.

STEP 2

We'll email you to provide your quote and confirm order details if applicable.

STEP 3

Execute the project with real-time communication, and deliver the final report promptly.