Invitrogen™ CyQUANT™ LDH and G6PD Cytotoxicity Assays

The Invitrogen™ CyQUANT™ LDH and G6PD Cytotoxicity Assays provide simple, reliable, and high-throughput methods for quantifying cellular cytotoxicity by detecting the release of cytosolic enzymes from damaged or dying cells.

• LDH Assays measure lactate dehydrogenase release — a robust and widely used marker of cell membrane damage.
• G6PD Assays measure glucose 6-phosphate dehydrogenase release — offering higher sensitivity and lower background than LDH assays.

These assays are compatible with microplate readers, support continuous monitoring, and are suitable for drug discovery, toxicity screening, and 3D cell model analysis.

Assay Options

LDH Cytotoxicity Assays (C20300, C20301, C20302, C20303)

• Colorimetric Format (490 nm) – Quantifies LDH via a coupled enzymatic reaction producing red formazan.
• Fluorescence Format (Ex 560 / Em 590 nm) – Quantifies LDH via NADH-mediated reduction of resazurin to resorufin for higher sensitivity and dynamic range.
• Detection Range: Works with adherent, suspension, and 3D cell models.
• Time to Result: Colorimetric (~30 min), Fluorescence (~10 min).

G6PD Cytotoxicity Assay (V23111)

• Higher Sensitivity: Detects as few as 500 cells.
• Lower Background: Produces cleaner signal compared to LDH assays.
• Fluorescence Detection: Ex 563 / Em 587 nm.
• Mechanism: Two-step enzymatic reaction producing resorufin proportional to G6PD release.

Key Features

• Flexible Detection – Colorimetric or fluorescence readouts.
• No Cell Lysis Required – Monitor the same culture over time.
• High Sensitivity – Detects low levels of enzyme release from minimal cell numbers.
• High-Throughput Compatible – Suitable for 96-well and higher-density formats.
• Robust & Reproducible – Minimal interference from culture media components.

Applications

• Quantitative cytotoxicity measurement in drug screening
• Antibody-dependent cell-mediated cytotoxicity (ADCC) assays
• Evaluation of immune cell-mediated killing
• Toxicity studies using 2D and 3D cell models
• Environmental and chemical hazard testing
• Longitudinal cytotoxicity monitoring in live cultures

Technical Specifications

Kit Contents (Varies by Catalog No.)

• Enzyme Substrate/Reagent Mix
• Assay Buffer
• Lysis Buffer
• Stop Solution
• LDH Positive Control

The Invitrogen™ CyQUANT™ LDH and G6PD Cytotoxicity Assays deliver robust, reproducible, and flexible solutions for cytotoxicity measurement. Whether using colorimetric LDH detection, high-sensitivity fluorescence LDH, or ultra-sensitive G6PD release detection, these kits are ideal for toxicology studies, immune cell killing assays, and drug discovery workflows.