3T3 Neutral Red Uptake Assay for Cytotoxicity
The 3T3 Neutral Red Uptake (NRU) Cytotoxicity Assay using a Neutral Red Uptake (NRU) viability endpoint is a 96-well cytotoxicity assay to assess the toxicity potential of a test material. The assay utilizes Balb/c 3T3 mouse fibroblasts to assess the systemic toxicity potential of a test material and may be used to predict in vivo rodent LD50 starting doses for acute oral systemic toxicity. Cytotoxicity caused by the test article is measured by a concentration-dependent reduction in neutral red dye uptake by the cells after exposure to a test material.
Healthy mammalian cells, when maintained in culture, continuously proliferate. A toxic chemical, regardless of site or mechanism of action, will interfere with this process and result in a reduction in viable cells relative to untreated controls. The viability of the cells can be assessed using a neutral red uptake endpoint. A decrease in the uptake of neutral red dye in treated cell cultures following a test chemical exposure is used to determine relative toxicity.
For specific assay procedures, please see Step-by-Step.
Assay Design: Quick Facts
Assay Model: Balb/c 3T3 cells seeded in a 96-well plate
Endpoint: IC50 (the concentration of the test material that causes a 50% decrease in viability, relative to solvent control)
Each assay includes a positive and negative control. For more information about testing your materials using this assay, please see Applications. Specialized protocols may be prepared as requested through consultation with an IIVS Study Director.