The GADD45a-GFP (GreenScreen HC™) reporter assay detects genotoxic damage in the human lymphoblastoid TK6 cell line and gives positive results for all classes of genotoxin, including mutagens, aneugens and clastogens.
3Hastwell PW, Webster TW, Tate M, Billinton N, Lynch AM, Harvey JS, Rees RW and Walmsley RM (2009) Mutagenesis 24(5); 455-463
|Test Article Concentration||9 serial dilutions, typically 2-fold; e.g. 1000, 500, 250, 125, 62.5, 31.3, 15.6, 7.8, 3.9 μg/mL|
|Incubation Time||GreenScreen HC™: 48 hour exposure time with results collected at 24 and 48 hour timepoints.
GreenScreen HC S9™: 3 hour exposure in the presence of S9, followed by 45 hour recovery and response time. Measurement at 48 hour timepoint.
|Quality Controls||1 % DMSO -Negative vehicle control
GreenScreen HC™: Methyl methanesulfonate (High 50 μg/ml, Low 10 μg/mL) – Positive control
GreenScreen HC S9™: Cyclophosphamide (High 25 μg/ml, Low 5 μg/mL) – Positive control
Non-fluorescent control TK6 strain
|Test Article Requirements||10 mg solid compound - Other compound preparations are acceptable|
|Metabolizing System||Typically, aroclor-1254 induced rat liver S9|
|Analysis Method||GreenScreen HC™ – Spectrophotometric reader
GreenScreen HC S9™ – Flow cytometer
|Data Delivery||Written report presenting overall results.
Lowest effective concentration (LEC) for positive genotoxicity and cytotoxicity results.
Excel worksheets with full graphical dose response data for genotoxicity and cytotoxicity.
GreenScreen HC™ has been validated extensively against a wide range of different in vitro and in vivo genotoxicity methods. Results are published within the literature1,3,4,5.
|Test||Positive (sensitivity)||Negative (specificity)||Concordance|
|In vitro cytogenetic||12/12||100||21/37||57||33/49||67|
|In vitro mammalian mutation||5/9||56||30/38||79||35/47||74|
|In vivo genotoxicity||12/12||100||40/45||89||52/57||91|
1 Birrell L et al. (2010) Mutation Research 695; 87-95
2 Jagger C et al., (2009) Mutagenesis 24(1); 35-50
3 Hastwell PW et al., (2009) Mutagenesis 24(5); 455-463
4 Knight AW et al., (2009) Regul Toxicol Pharmacol 55; 188-199
5 Knight AW et al., (2009) J Biomol Screen 14; 16-30
Learn more about toxicology in our popular Mechanisms of Drug-Induced Toxicity guide