Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Inter-Laboratory Variability in Ames Assay Results.
Author Knuiman, M. W. ; Laird, N. M. ; Louis, T. A. ;
CORP Author Harvard School of Public Health, Boston, MA. Dept. of Biostatistics.;Health Effects Research Lab., Research Triangle Park, NC.
Publisher c1987
Year Published 1987
Report Number EPA-R-813495; EPA/600/J-87/520;
Stock Number PB90-232273
Additional Subjects Salmonella typhimurium ; Variability ; Tables(Data) ; Graphs(Charts) ; Errors ; Research laboratories ; Reprints ; Mutagenicity tests ; Carcinogenicity tests ; Toxic substances ; Biotransformation
Library Call Number Additional Info Location Last
NTIS  PB90-232273 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 08/27/1990
Collation 14p
The Ames test is widely used in the screening of chemicals and compounds for potential carcinogenic effect. There is, however, considerable inter-laboratory variability in results from the assay. Using data from the RTI Collaborative Study of the EPA Ames Test Protocol, it is shown that their reported standard errors of estimates of mutagenicity fall far short of capturing day-to-day or laboratory-to-laboratory variation. The authors estimate the factors by which the standard errors must be inflated to account for these sources of variation. The laboratory protocol and previous studies suggest that much of this variation may be caused by factors that are relatively constant within days (e.g. technician, incubation temperature, S9 liver homogenate preparation) but vary over days and across laboratories. Therefore, such variation might be reduced through use of a reference compound tested on the same day and under the same conditions as the test chemical. This conjecture was, however, not supported by analyses that considered the positive control compound and a pure chemical as possible reference assay. (Copyright (c) Elsevier Science Publishers B.V. (Biomedical Division)).