Mouse lymphoma thymidine kinase gene mutation assay: follow-up meeting of the International Workshop on Genotoxicity Testing--Aberdeen, Scotland, 2003--Assay acceptance criteria, positive controls, and data evaluation.
The Mouse Lymphoma Assay (MLA) Workgroup of the International Workshop on Genotoxicity Testing (IWGT), comprised of experts from Japan, Europe, and the United States, met on August 29, 2003, in Aberdeen, Scotland, United Kingdom. This meeting of the MLA Workgroup was devoted to reaching a consensus on the appropriate approach to data evaluation and on acceptance criteria for both the positive and negative/vehicle controls. The Workgroup reached consensus on the acceptance criteria for both the agar and microwell versions of the MLA. Recommendations include acceptable ranges for mutant frequency, cloning efficiency, and suspension growth of the negative/vehicle controls and on criteria to define an acceptable positive control response. The recommendation for the determination of a positive/negative test chemical response includes both the requirement that the response exceeds a defined value [the global evaluation factor (GEF)] and that there also be a positive dose-response (evaluated by an appropriate statistical method).
Moore
Martha M
MM
National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079, USA. MMMoore@nctr.fda.gov
Honma
Masamitsu
M
Clements
Julie
J
Bolcsfoldi
George
G
Burlinson
Brian
B
Cifone
Maria
M
Clarke
Jane
J
Delongchamp
Robert
R
Durward
Robert
R
Fellows
Michael
M
Gollapudi
Bhaskar
B
Hou
Saimei
S
Jenkinson
Peter
P
Lloyd
Melvin
M
Majeska
Jenness
J
Myhr
Brian
B
O'Donovan
Michael
M
Omori
Takashi
T
Riach
Colin
C
San
Richard
R
Stankowski
Leon F
LF
Thakur
Ajit K
AK
Van Goethem
Freddy
F
Wakuri
Shinobu
S
Yoshimura
Isao
I
D000818:Animals; D001681:Biological Assay / Q000592:standards*; D008223:Lymphoma / Q000201:enzymology / Q000235:genetics; D051379:Mice; D009152:Mutagenicity Tests / Q000592:standards*; D009154:Mutation; D013937:Thymidine Kinase / Q000235:genetics*
D013937:Thymidine Kinase