A pre-validation transferability study of the GreenScreen HC GADD45a-GFP assay with a metabolic activation system (S9).
A new protocol has recently been developed and validated for the GreenScreen HC GADD45a-GFP genotoxicity reporter assay, enabling the incorporation of an S9 metabolic activation system into the assay. The S9 protocol employs flow-cytometric methodology for the detection of both reporter GFP fluorescence and propidium iodide fluorescence for the estimation of cellular viability. In the spirit of assay validation by bodies such as the European Centre for the Validation of Alternative Methods (ECVAM), the adapted metabolic activation protocol for the GADD45a-GFP assay has been undergoing 'pre-validation'. Results of phases I and II of this pre-validation, namely protocol refinement and protocol transfer, respectively, are presented here. In phase I the protocol was transferred to a second laboratory for initial assessment of method portability and subsequent refinement of the protocol. In phase II, the protocol was then transferred to two further laboratories along with the elaborated standard operating-procedure (SOP) for further assessment of transferability. The three transfer sites then undertook an assessment of the method's reproducibility by testing eight compounds. The outcome of the study was a refined protocol that was found to be highly transferable. It yielded 100% agreement in results between all four laboratories.
Billinton
Nicholas
N
Gentronix Ltd, CTF Building, 46 Grafton Street, Manchester M13 9NT, UK.
Bruce
Shannon
S
Hansen
Julia Rytter
JR
Hastwell
Paul W
PW
Jagger
Christopher
C
McComb
Catriona
C
Klug
Michelle L
ML
Pant
Kamala
K
Rabinowitz
Adam
A
Rees
Robert
R
Tate
Matthew
M
Vinggaard
Anne Marie
AM
Walmsley
Richard M
RM
D001711:Biotransformation; D018797:Cell Cycle Proteins; D002460:Cell Line; D049452:Green Fluorescent Proteins; D006801:Humans; D009152:Mutagenicity Tests / Q000379:methods*; D009687:Nuclear Proteins; D015203:Reproducibility of Results; D000097642:GADD45 Proteins
D018797:Cell Cycle Proteins; D049452:Green Fluorescent Proteins; D009687:Nuclear Proteins; C439070:GADD45A protein, human; D000097642:GADD45 Proteins