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Fetax interlaboratory validation study: Phase II testing
Author(s) -
GaudetHull Angela M.,
Rayburn James R.,
Bantle John A.,
Burton Dennis T.,
Turley Steven D.,
Dawson Douglas A.,
Dumont James N.,
Finch Robert A.,
Maurice Margaret A.,
Fort Douglas J.,
Linder Greg,
Buchwalter David
Publication year - 1994
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620131012
Subject(s) - bioassay , coefficient of variation , repeatability , toxicology , biology , chromatography , chemistry , genetics
The Frog Embryo Teratogenesis Assay— Xenopus (FETAX) is a 96 h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that helps in embryo staging and identifying malformations As part of the ASTM process, an interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FE TAX Six different laboratories participated in the study Each laboratory utilized one technician with the exception of one laboratory, which utilized two independent technicians In Phase I, FETAX proved to be more repeatable and reliable than many other bioassays However, some excessive variation was observed in a few laboratories Some of this variation may have been due to an initial lack of experience with the assay by some technicians Phase II, which is reported here, showed far less intralaboratory and interlaboratory variability than did Phase I Nonteratogens such as saccharin and sodium cyclamate showed the most consistent results, whereas more variability was observed for the teratogens caffeine and 5‐fluorouracil Interlaboratory coefficient of variation values for all FETAX end points ranged from 7 3 to 54 7% The minimum concentration to inhibit growth proved to be the most variable end point for three of the four test chemicals, whereas the LC50 and EC50 (malformation) proved to be less variable