Vector Titer Determination
Vector Titer Determination - Related Videos
08:35
Production and Titering of Recombinant Adeno-associated Viral Vectors
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Cited by 149 •
2011
Recombinant adeno-associated virus (rAAVs) vectors are becoming increasingly valuable for in vivo studies in animals. We describe how rAAVs can be produced in the laboratory and how these vectors can be titered to give an accurate reading of the number of infectious particles produced.
16:04
A Tetracycline-regulated Cell Line Produces High-titer Lentiviral Vectors that Specifically Target Dendritic Cells
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Cited by 6 •
2013
Here, we use retroviral transduction and concatemeric transfection to create a cell line that can express the components of a lentiviral vector (LV) in the absence of tetracycline. This LV encodes GFP and is pseudotyped with a glycoprotein, SVGmu, which is specific for a receptor on dendritic cells.
05:51
A Streamlined and Standardized Procedure for Generating High-Titer, High-Quality Adeno-Associated Virus Vectors Utilizing a Cell Factory Platform
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Cited by 1 •
2024
As the field of gene therapy continues to evolve, there is a growing need for innovative methods that can address these challenges. Here, a unique method is presented, which streamlines the process of generating high-yield and high-purity AAV vectors using a cell factory platform, meeting the quality standards for in vivo studies.
13:00
Plaque Assay: A Method to Determine Viral Titer as Plaque Forming Units (PFU)
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2023
Source: Tilde Andersson1, Rolf Lood1 1 Department of Clinical Sciences Lund, Division of Infection Medicine, Biomedical Center, Lund University, 221 00 Lund, Sweden Viruses that infect prokaryotic organisms, called bacteriophages or simply phages, were identified in the early 20th century by Twort (1) and d'Hérelle (2) independently. Phages have since been widely recognized for their therapeutic value (3) and their influence on human (4), as well as global, ecosystems (5). Current concerns have...
03:51
Assessing Lentiviral Titer Using an Enzyme-Linked Immunosorbent Assay
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2026
Source: Vijayraghavan, S., et al. Protocol for the Production of Integrase-deficient Lentiviral Vectors for CRISPR/Cas9-mediated Gene Knockout in Dividing Cells. J. Vis. Exp. (2017).This video demonstrates the use of a p24 ELISA to estimate viral titers of lentiviral vectors. The assay involves lysing viral particles to release p24, capturing it with specific antibodies, and detecting it with a peroxidase-linked system that produces a measurable color change. By comparing sample absorbance...
FAQs
Functional and physical titers answer different quality questions. A functional titer reflects vector material that produces a measurable transduction outcome under specified cell and assay conditions. A physical titer measures vector-associated material through nucleic acid or another physical readout. Comparing the two can reveal whether a preparation contains substantial material but relatively limited biological activity, supporting interpretation of dosing and quality.
Serial dilution makes the assay interpretable by placing samples across a range of exposure levels. Each dilution is applied to cultured cells, and the resulting reporter signal or nucleic acid measurement is related to the corresponding input dilution. This approach helps distinguish measurable transduction differences across samples and provides the experimental basis for calculating a functional titer.
Cell type and assay readout can change the measured functional titer, even when the vector preparation is unchanged. Neurons and glial cells may not generate identical transduction measurements under the same exposure, while reporter-based and nucleic-acid-based assays capture different aspects of the result. Titer values should therefore be interpreted with the cell system and measurement method clearly specified.
A basic workflow begins with a vector preparation and a planned series of dilutions. The diluted samples are used to expose cultured cells, followed by measurement of transduction through a reporter signal, nucleic acid measurement, or another assay readout. Results from the dilution series are then used to calculate functional titer instead of relying only on the starting sample concentration.
Reporter signals and nucleic acid measurements provide different routes for quantifying transduction, so the readout should match the experimental question. A reporter-based assay measures the resulting signal, whereas a nucleic acid assay measures genetic material through another type of readout. Recording the selected method is essential when comparing titers across vector preparations or experiments.
In neuroscience, titer determination helps standardize viral vector dosing for delivery to neurons and glial cells. Consistent input supports reproducibility in circuit-tracing experiments, gene-manipulation studies, and disease models. Titer information also helps investigators optimize dosing and assess whether differences between experiments reflect the vector preparation or the biological system being studied.