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).
National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079, USA. MMMoore@nctr.fda.gov
Martha M
MM
Moore
Masamitsu
M
Honma
Julie
J
Clements
George
G
Bolcsfoldi
Brian
B
Burlinson
Maria
M
Cifone
Jane
J
Clarke
Robert
R
Delongchamp
Robert
R
Durward
Michael
M
Fellows
Bhaskar
B
Gollapudi
Saimei
S
Hou
Peter
P
Jenkinson
Melvin
M
Lloyd
Jenness
J
Majeska
Brian
B
Myhr
Michael
M
O'Donovan
Takashi
T
Omori
Colin
C
Riach
Richard
R
San
Leon F
LF
Stankowski
Ajit K
AK
Thakur
Freddy
F
Van Goethem
Shinobu
S
Wakuri
Isao
I
Yoshimura
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