# A Novel Anti-Cadherin-19 Monoclonal Antibody (Ca19Mab-8) for Flow Cytometry, Western Blotting, and Immunohistochemistry

## TL;DR

A new monoclonal antibody, Ca19Mab-8, was developed to detect CDH19 with high specificity for use in research and potential clinical applications.

## Contribution

The development of a novel anti-CDH19 monoclonal antibody suitable for flow cytometry, Western blotting, and immunohistochemistry.

## Key findings

- Ca19Mab-8 specifically recognizes CDH19-overexpressed cells without binding to other cadherins.
- Ca19Mab-8 detects endogenous CDH19 in glioblastoma cells and human melanoma tissue.
- The antibody has a high dissociation constant (KD) of 9.0 × 10−9 M for CDH19.

## Abstract

The type II cadherin Cadherin-19 (CDH19) plays a crucial role in neural crest development. CDH19 regulates cell–cell junctions and migration by forming catenin–cytoskeleton complexes. Although anti-CDH19 monoclonal antibodies (mAbs) are used for specific applications such as Western blotting and immunohistochemistry (IHC), suitable anti-CDH19 mAbs for flow cytometry are limited. Therefore, developing mAbs that specifically recognize cell-surface-expressed CDH19 is essential for advancing both basic research and therapeutic strategies. Here, novel anti-human CDH19 mAbs (Ca19Mabs) were created using flow cytometry-based high-throughput screening. One clone, Ca19Mab-8 (IgG1, κ), specifically recognized CDH19-overexpressed Chinese hamster ovary-K1 cells but did not bind to other 21 CDHs (including both type I and type II CDHs) in flow cytometry. Additionally, Ca19Mab-8 recognized endogenous CDH19 in the human glioblastoma cell line LN229. The dissociation constant (KD) of Ca19Mab-8 for LN229/CDH19 was 9.0 × 10−9 M. Ca19Mab-8 also detected endogenous CDH19 in Western blotting. Furthermore, Ca19Mab-8 can detect CDH19 in IHC using human melanoma tissue. These findings suggest that Ca19Mab-8 is a novel mAb that detects cell-surface-expressed CDH19 with high specificity and is suitable for various applications in basic research. Therefore, Ca19Mab-8 has potential for clinical diagnosis and tumor therapy.