Research Round-Up: CST Anti-CAR Linker Antibodies in the Literature

Universal High-Sensitivity CAR T-cell Monitoring by Targeting Linker Sequences

Schwingen et al. (Front. Immunol. 2026) | DOI: 10.3389/fimmu.2026.1787951

Researchers compared CAR detection reagents for flow cytometry, comparing their performance for CD19-, BCMA-, and Claudin-6 CAR T-cell products. They compared specificity, sensitivity, and longitudinal monitoring of lymphoma and myeloma patients. According to the researchers, “These findings establish anti-Whitlow/218 and anti-G4S mAbs as sensitive, specific, and universal reagents for CAR detection across multiple targets, constructs, and species, providing a standardized platform for harmonization of CAR T-cell monitoring in preclinical, clinical trial, and diagnostic settings.” 

Use Case: 
Detect: To confirm CAR expression, the AF647 conjugates of Whitlow/218 linker (E3U7Q) Rabbit Monoclonal Antibody and G4S Linker (E7O2V) Rabbit Monoclonal Antibody clones were used for flow cytometry-based detection of various CAR cells, including Axi-cel, Tisa-cel, Ide-cel, Cilta-cel, and BNT211.

Development of Multivalent CAR T Cells as Dual Immunotherapy and Conditioning Agents

Bubb et al. (Mol Ther Oncol.) | DOI: 10.1016/j.omton.2025.200944

Researchers from Stanford University School of Medicine developed an extracellularly linked concatemeric trivalent cytokine "ELECTRIC," single-receptor, trivalent CAR T cell therapy targeting KIT, MPL, and FLT3 for acute myeloid leukemia (AML). This therapeutic approach eliminates malignant cells and conditions the bone marrow for stem cell transplantation without requiring genotoxic chemotherapy or irradiation. This study used the G4S Linker (E702V) Rabbit mAb to detect the trivalent CAR, which used the (G4S)3 linker to combine the three cytokine receptors into a single protein.

Use Case:

Detect: To detect CAR cells, the G4S Linker (E7O2V) Rabbit Monoclonal Antibody clone was used for flow cytometry-based detection of the trivalent CAR, targeting three key cytokines in hematopoietic development.

Linker-specific Monoclonal Antibodies Present a Simple & Reliable Detection Method for scFv-Based CAR NK cells

Schindler et al. (Molecular Therapy 2024) | DOI: 10.1016/j.omtm.2024.101328

CAR natural killer (NK) cells are being investigated in clinical trials for their potential advantages over CAR-T cell therapies, including their use as allogeneic cell therapies. This study evaluated the use of anti-CAR linker antibodies as a universal and sensitive tool for detecting CAR NK cells, including comparing them to other commonly used detection methods. The study demonstrates that linker-specific mAbs can detect different CAR NK cells in vitro, spiked in whole blood, and within patient-derived tumor spheroids with high specificity and sensitivity, providing an effective and almost universal alternative for scFv-based CAR detection. Additionally, the authors demonstrate that linker-specific antibodies can be used for functional testing and enrichment of CAR NK cells.

Use Cases: 

Detect: To confirm CAR expression, the Whitlow/218 linker (E3U7Q) Rabbit Monoclonal Antibody and G4S Linker (E7O2V) Rabbit Monoclonal Antibody clones were used for flow cytometry-based detection of various CAR constructs. 

Analyze: The Whitlow/218 linker (E3U7Q) Rabbit mAb and G4S Linker (E7O2V) Rabbit mAb clones were used in an activation assay to confirm their ability to selectively activate CAR NK cells (explore T-cell activation assays from CST).

Purify: The Whitlow/218 linker (E3U7Q) Rabbit mAb and G4S Linker (E7O2V) Rabbit mAb clones were used to enrich CAR NK cells using magnetic separation (explore magnetic bead CAR enrichment assays from CST). The authors demonstrated that the CAR NK cells did not become activated or compromised in their viability after purification.

Magnetic CAR T Cell Purification Using an Anti-G4S Linker Antibody

Harrer et al. (JIM 2024) | DOI: 10.1016/j.jim.2024.113667

This study introduced a novel CAR-T cell purification method using magnetic separation based on an anti-G4S linker antibody. The approach allowed for the enrichment of CAR-T cells to high purity levels without affecting their viability or functionality. The method was tested on CAR-T cells targeting CEA and Her2, as well as a dual-specific tandem CAR.

Use Case:

Purify: The G4S Linker (E7O2V) Rabbit Monoclonal Antibody clone was used to label CAR-T cells before magnetic-activated cell sorting (MACS) using a one-step protocol (explore magnetic bead CAR enrichment assays from CST), demonstrating efficient purification without impairing cell viability.

Chimeric Antigen Receptor T cells Against the IGHV4-34 B Cell Receptor Specifically Eliminate Neoplastic and Autoimmune B Cells

Cohen et al. (Science Translational Medicine 2026) | DOI: 10.1126/scitranslmed.adr9382

Researchers developed CART4-34, a targeted therapy designed to address the limitations of CD19-targeting CAR T cell therapies in treating B cell malignancies and systemic lupus erythematosus (SLE). By targeting the IGHV4-34 gene, this therapy offers high efficacy in preclinical models, reduces the risk of antigen-negative escape, and preserves healthy B cells. This paper tested short-hinge CAR T cells for cytotoxicity and anti-tumor activity.

Use Case:

Detect: To detect CAR cells, the PE version of the G4S Linker (E7O2V) Rabbit Monoclonal Antibody clone was used for flow cytometry-based detection of the short-hinge CAR4-34 constructs and their expression.