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Study Information
Study Attribute Value
CEBS Accession Number: 002-01934-0001-0000-0
Chemical Name: Cytembena
CASRN: 21739-91-3
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 404197_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: 07/10/1985    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 1026 460 0.448 9.20 25.5 0.000
Test Chemical Cytembena 
1         
 50 1033 695 0.673 13.90 32.0 50.063 
3         
 50 1011 685 0.678 13.70 32.0 51.122 
10         
 25 498 584 1.173 23.36 32.0 161.561 
30         
 0 0 0 0.000 0.00 32.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1025 653 0.637 13.06 25.5 42.095
Mitomycin-C 
 0.01      
 5 104 284 2.731 56.80 25.5 509.080
Trend: 14.510        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 08/21/1985    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         
 25 513 214 0.417 8.56 25.5 0.000
Test Chemical Cytembena 
10.1       
 25 511 268 0.524 10.72 25.5 25.724 
30         
 25 511 439 0.859 17.56 25.5 105.943 
40         
 25 508 541 1.065 21.64 25.5 155.292
Positive Control Mitomycin-C 
 0.001     
 25 508 316 0.622 12.64 25.5 49.117
Mitomycin-C 
 0.01      
 5 104 214 2.058 42.80 25.5 393.269
Trend: 13.509        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 07/10/1985    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 1045 419 0.401 8.38 25.5 0.000
Test Chemical Cytembena 
10         
 50 1034 577 0.558 11.54 25.5 39.174 
30         
 50 1036 554 0.535 11.08 32.0 33.368 
100         
 50 1039 787 0.757 15.74 32.0 88.913 
300         
 0 0 0 0.000 0.00 32.0 N/A
Positive Control Cyclophosphamide 
 0.4       
 50 1037 773 0.745 15.46 25.5 85.910
Cyclophosphamide 
2         
 5 105 210 2.000 42.00 25.5 398.807
Trend: 10.138        
Probability: 0.000