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Study Information
Study Attribute Value
CEBS Accession Number: 002-01787-0001-0000-6
Chemical Name: C.I. Direct brown 95
CASRN: 16071-86-6
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 754489_SCE
Study Result: Equivocal

Study Result: Equivocal
Activation Trial Trial Call
No Activation  1  Negative 
No Activation  2  Negative 
Induced Rat Liver S9  1_S9  Negative 
Induced Rat Liver S9  2_S9  Weakly Positive 
Induced Rat Liver S9  3_S9  Negative 
Induced Rat Liver S9  4_S9  Positive 

Trial #: 1    Activation: No Activation    Date: 02/24/1982    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 Water 
0         
 50 1050 417 0.397 8.34 26.0 0.000
Test Chemical C.I. Direct brown 95 
3.8       
 50 1051 422 0.402 8.44 26.0 1.103 
12         
 50 1049 371 0.354 7.42 26.0 -10.946 
38         
 50 1049 402 0.383 8.04 26.0 -3.505 
120         
 50 1048 438 0.418 8.76 26.0 5.236 
380         
 50 1049 413 0.394 8.26 28.0 -0.865
Positive Control Mitomycin-C 
 0.005     
 50 1047 810 0.774 16.20 26.0 94.801
Trend: 0.381        
Probability: 0.352        

Trial #: 2    Activation: No Activation    Date: 05/19/1982    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 Water 
0         
 50 1046 375 0.359 7.50 26.0 0.000
Test Chemical C.I. Direct brown 95 
12.2       
 50 1049 392 0.374 7.84 26.0 4.234 
38         
 50 1048 414 0.395 8.28 26.0 10.189 
122         
 50 1047 439 0.419 8.78 26.0 16.955 
380         
 50 1043 399 0.383 7.98 26.0 6.706
Positive Control Mitomycin-C 
 0.005     
 25 525 713 1.358 28.52 26.0 278.818
Trend: 1.547        
Probability: 0.061        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 02/24/1982    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 Water 
0         
 50 1048 551 0.526 11.02 26.0 0.000
Test Chemical C.I. Direct brown 95 
12         
 50 1047 511 0.488 10.22 26.0 -7.171 
38         
 50 1046 586 0.560 11.72 26.0 6.555 
120         
 50 1050 534 0.509 10.68 26.0 -3.270 
380         
 50 1047 626 0.598 12.52 26.0 13.720
Positive Control Cyclophosphamide 
1         
 50 1048 729 0.696 14.58 26.0 32.305
Trend: 2.302        
Probability: 0.011        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 05/19/1982    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 Water 
0         
 150 3131 1584 0.506 10.56 26.0 0.000
Test Chemical C.I. Direct brown 95 
250         
 50 1043 620 0.594 12.40 28.0 17.499 
300         
 45 940 535 0.569 11.89 28.0 12.500 
350         
 35 730 480 0.658 13.71 28.0 29.971 
400         
 50 1043 606 0.581 12.12 28.0 14.846
Positive Control Cyclophosphamide 
1         
 50 1046 872 0.834 17.44 26.0 64.783
Trend: 4.335        
Probability: 0.000        

Trial #: 3_S9    Activation: Induced Rat Liver S9    Date: 06/10/1982    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 Water 
0         
 50 1045 419 0.401 8.38 26.0 0.000
Test Chemical C.I. Direct brown 95 
47.5       
 50 1048 352 0.336 7.04 26.0 -16.231 
95         
 50 1042 353 0.339 7.06 26.0 -15.509 
190         
 50 1043 435 0.417 8.70 26.0 4.018 
380         
 22 454 185 0.407 8.41 28.0 1.629
Positive Control Cyclophosphamide 
1.5       
 50 1049 1355 1.292 27.10 26.0 222.156
Trend: 1.144        
Probability: 0.126        

Trial #: 4_S9    Activation: Induced Rat Liver S9    Date: 09/16/1982    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 Water 
0         
 50 1048 398 0.380 7.96 26.0 0.000
Test Chemical C.I. Direct brown 95 
200         
 50 1049 428 0.408 8.56 28.0 7.435 
250         
 50 1052 593 0.564 11.86 28.0 48.428 
300         
 50 1049 508 0.484 10.16 28.0 27.517 
350         
 50 1046 549 0.525 10.98 28.0 38.203 
400         
 50 1051 479 0.456 9.58 28.0 20.008
Positive Control Cyclophosphamide 
1         
 50 1049 981 0.935 19.62 26.0 146.247
Trend: 4.079        
Probability: 0.000