COVID-19 is an emerging, rapidly evolving situation.

Get the latest public health information from CDC and research information from NIH.

U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Share This:
Study Information
Study Attribute Value
CEBS Accession Number: 002-01391-0003-0000-9
Chemical Name: 3,3'-Dimethylbenzidine dihydrochloride
CASRN: 612-82-8
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 979364_SCE
Study Result: Positive

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

Trial #: 1    Activation: No Activation    Date: 04/09/1982    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 1033 413 0.400 8.26 26.0 0.000
Negative (Not Specified) 
0         
 50 1041 391 0.376 7.82 26.0 -6.054
Test Chemical 3,3'-Dimethylbenzidine dihydrochloride 
 0.5       
 50 1044 420 0.402 8.40 26.0 0.623 
1.6       
 50 1047 429 0.410 8.58 26.0 2.485 
5         
 50 1038 451 0.434 9.02 26.0 8.675 
16         
 50 1047 486 0.464 9.72 26.0 16.102 
50         
 50 1039 638 0.614 12.76 26.0 53.587
Positive Control Mitomycin-C 
 0.005     
 50 1049 1578 1.504 31.56 26.0 276.255
Trend: 7.319        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 07/10/1982    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 1044 381 0.365 7.62 26.0 -20.688
3,3'-Dimethylbenzidine dihydrochloride 
0         
 50 1041 479 0.460 9.58 26.0 0.000
Test Chemical 3,3'-Dimethylbenzidine dihydrochloride 
5         
 50 1046 465 0.445 9.30 26.0 -3.387 
10         
 50 1044 576 0.552 11.52 26.0 19.905 
20         
 50 1038 605 0.583 12.10 26.0 26.670 
40         
 50 1035 767 0.741 15.34 26.0 61.054 
60         
 50 1041 862 0.828 17.24 26.0 79.958 
80         
 0 0 0 0.000 0.00 26.0 N/A
Positive Control Mitomycin-C 
 0.005     
 50 1050 1393 1.327 27.86 26.0 188.322
Mitomycin-C 
 0.01      
 50 1045 2049 1.961 40.98 26.0 326.129
Trend: 13.686        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 04/09/1982    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 1042 464 0.445 9.28 26.0 0.000
Negative (Not Specified) 
0         
 50 1039 475 0.457 9.50 26.0 2.666
Test Chemical 3,3'-Dimethylbenzidine dihydrochloride 
1.6       
 50 1044 417 0.399 8.34 26.0 -10.301 
5         
 50 1049 435 0.415 8.70 26.0 -6.876 
16         
 50 1039 460 0.443 9.20 26.0 -0.576 
50         
 50 1032 407 0.394 8.14 26.0 -11.435 
160         
 50 1038 439 0.423 8.78 26.0 -5.023 
500         
 50 1037 484 0.467 9.68 26.0 4.813
Positive Control Cyclophosphamide 
2         
 50 1047 3560 3.400 71.20 26.0 663.577
Trend: 0.852        
Probability: 0.197