ID#

241

Location:

Exhibit Hall

Time of Presentation:

March 22, 9:30 AM - 12:30 PM

Category:

In Vitro/Alternative Animal Models I

Data Collection and Analysis Systems for an In Vitro Cytotoxicity Validation Study
J.A. Strickland¹, M.W. Paris¹, H. Raabe², J.H. Haseman³, S. Casati⁴, R. Clothier⁵, C. Cao⁶, P. Crockett⁷, R.R. Tice¹, W.S. Stokes³
1. NICEATM and ILS Inc., RTP, NC
2. IIVS, Gaithersburg, MD
3. NIEHS, RTP, NC
4. ECVAM, JRC, Ispra, Italy
5. University of Nottingham, Nottingham, UK
6. U.S. Army ECBC, APG, MD
7. Analytical Sciences Inc., RTP, NC

NICEATM and ECVAM designed a multi-laboratory validation study to evaluate two in vitro basal cytotoxicity test methods using 72 coded chemicals with a wide range of acute oral toxicity. The study was designed in three phases to allow adjustments in the cytotoxicity protocols and data collection and evaluation procedures before the majority of the chemicals are tested in Phase III. An Excel® template was distributed to the participating labs for collection of raw data, analysis for outliers among dose replicates, documentation of materials and procedures, simple graphical analysis of dose-response, and transformation of data to the proper format for further analysis. Rather than applying a linear interpolation technique to the dose response to calculate the IC₅₀, GraphPad Prism® software was used to perform a Hill function analysis. IC₂₀, IC₅₀, and IC₈₀ values and associated 95% confidence limits were calculated, and the data and fitted model were graphed. Initial criteria for an acceptable dose-response for individual tests included one data point between 10 & 50% viability, one data point between 50 & 90% viability, and r²≥0.8. A Prism® template was distributed to the laboratories to automate and provide uniformity of analysis. To increase the speed of data collection and evaluation of the analyses by the Study Management Team (SMT) and consulting biostatisticians, the laboratories submitted Excel® and Prism® data files by e-mail. Results compiled by the SMT were returned to the originating laboratories for audit to ensure accurate transmission of data. Implementation of these procedures shows that automated data collection in relatively common, easy-to-use electronic formats can facilitate uniformity of data collection and analysis. Supported by: N01-ES 35504; EPA IAG DW-75-93893601-0; European Commission 19416-2002-04 F2ED ISP GB.