Unit

UNIT 20.4 Neutral Red Uptake Cytotoxicity Tests for Estimating Starting Doses for Acute Oral Toxicity Tests

  1. William S. Stokes1,
  2. Silvia Casati2,
  3. Judy Strickland3,
  4. Michael Paris3

Published Online: 1 MAY 2008

DOI: 10.1002/0471140856.tx2004s36

Current Protocols in Toxicology

Current Protocols in Toxicology

How to Cite

Stokes, W. S., Casati, S., Strickland, J. and Paris, M. 2008. Neutral Red Uptake Cytotoxicity Tests for Estimating Starting Doses for Acute Oral Toxicity Tests. Current Protocols in Toxicology. 36:20.4:20.4.1–20.4.20.

Author Information

  1. 1

    The National Toxicology Program (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), Research Triangle Park, North Carolina

  2. 2

    European Centre for the Validation of Alternative Methods (ECVAM), Ispra, Italy

  3. 3

    Integrated Laboratory Systems (ILS), Research Triangle Park, North Carolina

Publication History

  1. Published Online: 1 MAY 2008
  2. Published Print: MAY 2008

Abstract

In vitro cytotoxicity assays can be used as alternative toxicity tests to reduce the total number of animals needed for acute oral toxicity tests. This unit describes two methods for determining the in vitro cytotoxicity of test substances using neutral red uptake (NRU) and using the in vitro data to determine starting doses for in vivo acute oral systemic toxicity tests, e.g., the up-and-down procedure or the acute toxic class method. The use of the NRU methods to determine starting doses for acute oral toxicity tests may reduce the number of animals required, and for relatively toxic substances, this approach may also reduce the number of animals that die or require humane euthanasia due to severe toxicity. An interlaboratory validation study has demonstrated that the methods are useful and reproducible for these purposes. Two standardized protocols provide details for performing NRU tests with rodent and human cells. Curr. Protoc. Toxicol. 36:20.4.1-20.4.20. © 2008 by John Wiley & Sons, Inc.

Keywords:

  • in vitro;
  • cytotoxicity;
  • alternative;
  • neutral red;
  • 3T3;
  • keratinocyte