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Study Information
Study Attribute Value
CEBS Accession Number: 002-01694-0002-0000-4
Chemical Name: Benzidine
CASRN: 92-87-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 993740_CA
Study Result: Positive

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

Trial #:1   Activation: No Activation    Date: 12/09/1981    Harvest Time: 14 hour(s)   Trial Call: Negative   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide 
0         
 100 3 0.030 3.0 0 0.000 0.0 3 0.030 3.0 0 0.000 0.0
Test Chemical: Benzidine 
5         
 100 4 0.040 4.0 0 0.000 0.0 4 0.040 4.0 0 0.000 0.0 
16         
 100 6 0.060 6.0 2 0.020 2.0 4 0.040 4.0 0 0.000 0.0 
50         
 100 10 0.100 8.0 2 0.020 2.0 8 0.080 8.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.05      
 100 19 0.190 17.0 10 0.100 10.0 9 0.090 7.0 0 0.000 0.0
Triethylenemelamine 
 0.15      
 100 28 0.280 25.0 5 0.050 5.0 23 0.230 21.0 0 0.000 0.0
Trend: 1.704 1.801 1.574  
Probability: 0.044 0.036 0.058  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 12/09/1981    Harvest Time: 14 hour(s)   Trial Call: Positive   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide 
0         
 100 4 0.040 3.0 0 0.000 0.0 4 0.040 3.0 0 0.000 0.0
Test Chemical: Benzidine 
50         
 100 12 0.120 7.0 5 0.050 4.0 7 0.070 5.0 0 0.000 0.0 
160         
 100 21 0.210 16.0 17 0.170 12.0 4 0.040 4.0 0 0.000 0.0 
500         
 100 30 0.300 17.0 16 0.160 14.0 14 0.140 8.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
15         
 100 33 0.330 27.0 13 0.130 11.0 20 0.200 17.0 0 0.000 0.0
Trend: 3.686 4.248 1.433  
Probability: 0.000 0.000 0.076