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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  Negative 
No Activation  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