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Study Information
Study Attribute Value
CEBS Accession Number: 002-01389-0001-0000-4
Chemical Name: 3,3'-Dimethoxybenzidine
CASRN: 119-90-4
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 013473_SCE
Study Result: Positive

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

Trial #: 1    Activation: No Activation    Date: 09/17/1980    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 Negative (Not Specified) 
0         
 50 1040 292 0.281 5.84 26.0 -16.169
Dimethyl Sulfoxide 
0         
 50 1048 351 0.335 7.02 26.0 0.000
Test Chemical 3,3'-Dimethoxybenzidine 
6.25      
 32 660 195 0.295 6.09 26.0 -11.785 
12.5       
 50 1043 382 0.366 7.64 26.0 9.354 
25         
 50 1040 1134 1.090 22.68 26.0 225.562 
50         
 45 950 361 0.380 8.02 26.0 13.459 
100         
 50 1035 516 0.499 10.32 29.0 48.855 
200         
 0 0 0 0.000 0.00 29.0 N/A
Positive Control Triethylenemelamine 
 0.015     
 15 313 409 1.307 27.27 26.0 290.151
Trend: 8.926        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 11/21/1980    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 1012 428 0.423 8.56 26.5 0.000
Negative (Not Specified) 
0         
 50 1015 406 0.400 8.12 26.5 -5.421
Test Chemical 3,3'-Dimethoxybenzidine 
12.5       
 50 986 477 0.484 9.54 26.5 14.387 
25         
 50 1013 464 0.458 9.28 26.5 8.304 
50         
 50 1008 314 0.312 6.28 26.5 -26.344 
100         
 50 1019 557 0.547 11.14 31.5 29.246 
150         
 50 184 200 1.087 4.00 31.5 157.009
Positive Control Triethylenemelamine 
15         
 50 1030 2436 2.365 48.72 26.5 459.212
Trend: 5.038        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 09/17/1980    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 1048 304 0.290 6.08 26.0 0.000
Negative (Not Specified) 
0         
 50 1046 298 0.285 5.96 26.0 -1.786
Test Chemical 3,3'-Dimethoxybenzidine 
125         
 50 1040 310 0.298 6.20 26.0 2.758 
250         
 50 1046 300 0.287 6.00 26.0 -1.127 
500         
 50 1039 461 0.444 9.22 26.0 52.958 
2500         
 50 1034 384 0.371 7.68 26.0 28.026 
5000         
 50 1037 480 0.463 9.60 29.0 59.570
Positive Control Cyclophosphamide 
1.5       
 50 1047 1943 1.856 38.86 29.0 539.755
Trend: 7.544        
Probability: 0.000