Bantle J A, Finch R A, Burton D T, Fort D J, Dawson D A, Linder G, Rayburn J R, Hull M, Kumsher-King M, Gaudet-Hull A M, Turley S D
Department of Zoology, Oklahoma State University, Stillwater 74078, USA.
J Appl Toxicol. 1996 Nov-Dec;16(6):517-28. doi: 10.1002/(SICI)1099-1263(199611)16:6<517::AID-JAT385>3.0.CO;2-R.
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 aids in embryo staging and identifying malformations. As part of the ASTM process, a three-phase interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FETAX. Seven different participants collaborated in the study. In Phase I, FETAX proved to be more repeatable and reliable than many bioassays. However, some excessive variation was observed in a few laboratories. An initial lack of assay experience by some technicians caused variation. Phase II showed far less intra- and interlaboratory variability than Phase I. Non-teratogens showed the most consistent results, while more variability was observed for the two teratogens tested. Interlaboratory coefficient of variation values for all endpoints ranged from 7.3 to 54.7. Phase III--Part 1, using coded samples and test concentration ranges selected by each laboratory, showed results similar to Phase I. Analysis of the causes of variation suggested that some technicians judged some embryos to be malformed while others consistently judged similar embryos as normal. Concentration ranges tested by some of the laboratories varied greatly and a new protocol for selecting concentrations for initial testing was written to reduce variation from this source. Testing to date suggests that FETAX is as repeatable and reliable as other standard bioassays.
非洲爪蟾胚胎致畸试验（FETAX）是一项为期96小时的全胚胎发育毒性筛选试验，当采用体外代谢活化系统时，可用于生态毒理学研究及检测哺乳动物发育毒性物质。美国材料与试验协会（ASTM）已发布了一份关于进行FETAX试验的标准化指南，以及一本辅助胚胎分期和识别畸形的配套图谱。作为ASTM流程的一部分，开展了一项三阶段实验室间验证研究，以评估FETAX的可重复性和可靠性。七家不同的机构参与了该研究。在第一阶段，FETAX被证明比许多生物测定法更具可重复性和可靠性。然而，在一些实验室中观察到了一些过度的变异。一些技术人员最初缺乏试验经验导致了变异。第二阶段显示，实验室内部和实验室之间的变异性远低于第一阶段。非致畸剂显示出最一致的结果，而在所测试的两种致畸剂中观察到了更多的变异性。所有终点的实验室间变异系数值范围为7.3至54.7。第三阶段的第一部分，使用各实验室选择的编码样品和测试浓度范围，结果与第一阶段相似。对变异原因的分析表明，一些技术人员将一些胚胎判定为畸形，而另一些人则始终将类似的胚胎判定为正常。一些实验室测试的浓度范围差异很大，因此编写了一份新的初始测试浓度选择方案，以减少这一来源的变异。迄今为止的测试表明，FETAX与其他标准生物测定法一样具有可重复性和可靠性。
