title: Automation of an in vitro cytotoxicity assay used to estimate starting doses in acute oral systemic toxicity tests.
abstract: Application of High Throughput Screening (HTS) to the regulatory safety assessment of chemicals is still in its infancy but shows great promise in terms of facilitating better understanding of toxicological modes-of-action, reducing the reliance on animal testing, and allowing more data-poor chemicals to be assessed at a reasonable cost. To promote the uptake and acceptance of HTS approaches, we describe in a stepwise manner how a well known cytotoxicity assay can be automated to increase throughput while maintaining reliability. Results generated with selected reference chemicals compared very favourably with data obtained from a previous international validation study concerning the prediction of acute systemic toxicity in rodents. The automated assay was then included in a formal ECVAM validation study to determine if the assay could be used for binary classification of chemicals with respect to their acute oral toxicity, using a threshold equivalent to a dose of 2000 mg/kg b.w. in a rodent bioassay (LD50). This involved the blind-testing of 56 reference chemicals on the HTS platform to produce concentration-response and IC50 data. Finally, the assay was adapted to a format more suited to higher throughput testing without compromising the quality of the data obtained.
authors.affiliation: Institute for Health and Consumer Protection, European Commission Joint Research Centre, 21027 Ispra (VA), Italy.
authors.forename: Mounir
authors.initials: M
authors.lastname: Bouhifd
authors.forename: Gilles
authors.initials: G
authors.lastname: Bories
authors.forename: Juan
authors.initials: J
authors.lastname: Casado
authors.forename: Sandra
authors.initials: S
authors.lastname: Coecke
authors.forename: Hedvig
authors.initials: H
authors.lastname: Norlén
authors.forename: Nicholaos
authors.initials: N
authors.lastname: Parissis
authors.forename: Robim M
authors.initials: RM
authors.lastname: Rodrigues
authors.forename: Maurice P
authors.initials: MP
authors.lastname: Whelan
mesh_terms: D016475:3T3 Cells; D000826:Animal Testing Alternatives; D000818:Animals; D001331:Automation; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects*; D003627:Data Interpretation, Statistical; D023381:Endpoint Determination; D057166:High-Throughput Screening Assays; D007928:Lethal Dose 50; D051379:Mice; D012984:Software; D023382:Toxicity Tests, Acute / Q000295:instrumentation* / Q000379:methods