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Study Information
Study Attribute Value
CEBS Accession Number: 002-01135-0001-0000-3
Chemical Name: 1-Phenyl-2-thiourea
CASRN: 103-85-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 575473_SCE
Study Result: Positive

Study Result: Positive
Activation Trial Trial Call
No Activation  1  Test Failure 
Induced Rat Liver S9  1_S9  Weakly Positive 
Induced Rat Liver S9  2_S9  Positive 

Trial #: 1    Activation: No Activation    Date: 12/05/1984    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 Dimethyl Sulfoxide 
0         
 50 1041 462 0.444 9.24 26.3 0.000
Test Chemical 1-Phenyl-2-thiourea 
5.01      
 50 1040 430 0.413 8.60 26.3 -6.837 
17         
 50 1041 394 0.378 7.88 26.3 -14.719 
50.11      
 50 1035 444 0.429 8.88 26.3 -3.339 
167         
 50 1037 408 0.393 8.16 30.9 -11.348 
501.11      
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1033 522 0.505 10.44 26.3 13.862
Mitomycin-C 
 0.01      
 5 107 158 1.477 31.60 26.3 232.722
Trend: -1.388        
Probability: 0.917        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 12/05/1984    Trial Call: Weakly Positive   
  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 375 0.357 7.50 26.3 0.000
Test Chemical 1-Phenyl-2-thiourea 
167         
 50 1046 381 0.364 7.62 26.3 1.891 
501.11      
 50 1032 411 0.398 8.22 26.3 11.405 
1700         
 50 1041 482 0.463 9.64 30.9 29.521 
5000         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.4       
 50 1047 755 0.721 15.10 26.3 101.718
Cyclophosphamide 
2         
 5 102 187 1.833 37.40 26.3 412.844
Trend: 4.052        
Probability: 0.000        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 01/15/1985    Trial Call: Positive   
  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 1041 345 0.331 6.90 25.8 0.000
Test Chemical 1-Phenyl-2-thiourea 
200         
 50 1045 527 0.504 10.54 31.0 52.169 
2500         
 50 1038 449 0.433 8.98 31.0 30.521 
3000         
 50 1040 465 0.447 9.30 31.0 34.912 
3500         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.4       
 50 1049 688 0.656 13.76 25.8 97.899
Cyclophosphamide 
2         
 5 105 236 2.248 47.20 25.8 578.195
Trend: 2.355        
Probability: 0.009