Anti-CD19/CD22 Bispecific CAR Lentivirus (Clones FMC63/m971 ScFv-CD8-4-1BB-CD3ζ)

What it means: The CAR Target is CD19/CD22 (Bispecific) — the cell-surface antigen the CAR T cell will recognize and attack.

Why it matters:

• Determines which tumor cells or disease-relevant cells the engineered T cell will target.
• Validate that your target cells express CD19/CD22 (Bispecific) before transduction to confirm assay suitability.

How to interpret here: This lentivirus encodes a CAR construct specific to CD19/CD22 (Bispecific) (FMC63 / m971). Use as a positive control for CD19/CD22 (Bispecific)-directed CAR-T evaluation or to generate CAR-T research reagents.

What it means: The CAR uses CD8 hinge & TM · 4-1BB · CD3ζ for activation and co-stimulation.

Why it matters:

• The 4-1BB (CD137) co-stimulatory domain enhances T cell persistence and metabolic fitness compared to CD28.
• CD3ζ provides primary activation signaling; the CD8 hinge and transmembrane domain stabilize CAR surface expression.

How to interpret here: This is a 2nd-generation CAR architecture with CD8 hinge & TM · 4-1BB · CD3ζ, consistent with the design used in FDA-approved CAR-T therapies.

What it means: The backbone is an HIV-based, VSV-G-pseudotyped lentiviral vector.

Why it matters:

• VSV-G pseudotyping provides broad tropism, enabling transduction of virtually all mammalian cell types including primary T cells.
• The HIV-based lentiviral backbone supports stable genomic integration, allowing permanent CAR expression in transduced cells.

How to interpret here: The HIV-based VSV-G backbone enables efficient transduction of primary human T cells — the gold standard for CAR-T cell manufacturing research.

What it means: The lentivirus carries a Puromycin resistance gene (if present).

Why it matters:

• Puromycin selection allows rapid elimination of non-transduced cells, typically within 3–5 days post-treatment.
• Determine the optimal puromycin concentration for your cell line by kill-curve assay before initiating selection.

How to interpret here: Use Puromycin selection to enrich for CAR-expressing cells in your experimental population.

What it means: This product requires Biosafety Level 2 (BSL-2) containment.

Why it matters:

• BSL-2 is required because the lentiviral particles contain recombinant nucleic acids, even though they are replication-incompetent.
• Work must be performed in a certified BSC (Biological Safety Cabinet) with appropriate PPE and institutional IBC approval.

How to interpret here: Ensure your facility is authorized for BSL-2 work before ordering. This is required regardless of the SIN design of the vector.

What it means: Each lot is supplied as 50 µl at a functional titer of ≥10⁸ TU/ml.

Why it matters:

• Titer (TU/ml) determines the volume needed for a given MOI (multiplicity of infection) in your transduction experiment.
• Titers are lot-specific; the exact value for each lot is provided on the Certificate of Analysis shipped with the product.

How to interpret here: Use this titer (≥10⁸ TU/ml) as your starting point to calculate the volume needed for a target MOI of 5–20 TU/cell in typical T cell or target cell transductions.

What it means: This lentivirus must be stored at −80°C immediately upon receipt.

Why it matters:

• Viral titers decrease significantly with each freeze-thaw cycle; even a single thaw and re-freeze can reduce infectivity by 50% or more.
• Aliquot into single-use volumes upon receipt to avoid repeated freeze-thaw cycles during your experiments.

How to interpret here: Store at −80°C and plan single-use aliquots. Titer values stated are for freshly thawed material.