Cyto-Cellect® Human IgG Kappa and Viability Probes Combined

Enhancing Cell Line Development in Cyto-Mine^® Chroma

Discover how combining the Cyto-Cellect^® Human IgG Kappa Assay Kit with our Viability Probe enables real-time, multiplexed detection of viable IgG-secreting cells in Cyto-Mine^® Chroma.

We’ll also discuss how this approach enhances therapeutic cell line development.

Author: Romina Durigon

Keywords:  Cell line development, antibody discovery

When we launched Cyto-Mine® Chroma we knew we were addressing a need – the ability to multiplex as their needs were evolving. For example, some of our customers were interested in how they could detect not only the cells that are secreting human IgG, but also making sure to exclude any that aren’t viable.

Our R&D team got to work to determine how we could best achieve this – leading to the launch of our Viability Probe. This has been optimized for use  in conjuction with our Cyto-Cellect® assay kits. We’ve also created a series of protocols to provide further proof of principle as to how this can be used in combination with different assay types including bead-based as well as FRET assays. If you’d like to find out more about these, please visit our Knowledge Hub!

In this post, we’ll focus on how combining Cyto-Cellect® Human IgG Kappa with the Viability Probe works and how this impacts Cell Line Development workflows. 

At the core of this approach is Cyto-Cellect® human IgGk FRET probes, which have been validated for specific binding to CHO cell-secreted human IgGk, and a customised viability dye that selectively targets apoptotic and necrotic cell membranes (Figure 1). This enables simultaneous real-time detection of human IgG-secreting cells and the identification of apoptotic and necrotic cells across all stages – from early apoptosis to late apoptosis and necrosis. 

Figure 1: Schematic of the Cyto-Cellect® human IgG kappa and Viability Assay Kit in action. Each picodroplet encapsulates a single cell, a viability probe consisting of Annexin V conjugated to a far-red fluorophore (red particles) and a pair of IgG-specific fluorescent probes. In the presence of an apoptotic or necrotic cell, Annexin V binds to PS residues exposed on the extracellular side of the cell membrane, leading to an increase in the far-red signal (left). In the presence of a live cell and an IgG-secreting cell, the donor and Acceptor FRET probes bind to human IgGs, forming a ternary FRET complex and triggering fluorescence changes in the green and orange channels (right).