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Study Information
Study Attribute Value
CEBS Accession Number: 002-02971-0001-0000-2
Chemical Name: Trimethylthiourea
CASRN: 2489-77-2
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 652396_SCE
Study Result: Not a Valid Test

Study Result: Not a Valid Test
Activation Trial Trial Call
No Activation  1  Test Failure 
Induced Rat Liver S9  1_S9  Negative 

Trial #: 1    Activation: No Activation    Date: 04/19/1984    Trial Call: Test Failure   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Negative (Not Specified) 
0         
 50 1050 509 0.485 10.18 26.0 -23.677
Dimethyl Sulfoxide 
0         
 50 1047 665 0.635 13.30 26.0 0.000
Test Chemical Trimethylthiourea 
16.7       
 50 1050 538 0.512 10.76 26.0 -19.329 
50         
 50 1049 515 0.491 10.30 26.0 -22.704 
100         
 50 1050 650 0.619 13.00 26.0 -2.535
Positive Control Mitomycin-C 
 0.0015    
 50 1046 780 0.746 15.60 26.0 17.405
Mitomycin-C 
 0.01      
 5 105 261 2.486 52.20 26.0 291.360
Trend: -0.961        
Probability: 0.832        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 04/19/1984    Trial Call: Negative   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Dimethyl Sulfoxide 
0         
 50 1049 551 0.525 11.02 26.0 0.000
Test Chemical Trimethylthiourea 
16.7       
 50 1050 557 0.530 11.14 26.0 0.993 
50         
 50 1050 521 0.496 10.42 26.0 -5.535 
100         
 50 1050 562 0.535 11.24 26.0 1.899
Positive Control Cyclophosphamide 
 0.4       
 50 1048 810 0.773 16.20 26.0 47.146
Cyclophosphamide 
2         
 5 105 220 2.095 44.00 26.0 298.894
Trend: -0.155        
Probability: 0.562