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Study Information
Study Attribute Value
CEBS Accession Number: 002-01774-0001-0000-2
Chemical Name: C.I. Direct black 38
CASRN: 1937-37-7
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 325575_SCE
Study Result: Negative

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

Trial #: 1    Activation: No Activation    Date: 12/17/1986    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 Medium 
0         
 50 1047 452 0.432 9.04 26.0 0.000
Test Chemical C.I. Direct black 38 
1.6       
 50 1050 374 0.356 7.48 26.0 -17.493 
5         
 50 1052 382 0.363 7.64 26.0 -15.888 
16         
 50 1049 390 0.372 7.80 26.0 -13.881 
50         
 32 672 262 0.390 8.19 26.0 -9.689
Positive Control Mitomycin-C 
 0.0E-4    
 50 1050 551 0.525 11.02 26.0 21.554
Mitomycin-C 
 0.005     
 10 210 328 1.562 32.80 26.0 261.795
Trend: -1.324        
Probability: 0.907        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 12/17/1986    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 Medium 
0         
 50 1050 425 0.405 8.50 26.0 0.000
Test Chemical C.I. Direct black 38 
16         
 50 1052 380 0.361 7.60 26.0 -10.758 
50         
 50 1049 429 0.409 8.58 26.0 1.037 
160         
 50 1045 459 0.439 9.18 26.0 8.517 
500         
 50 1049 417 0.398 8.34 26.0 -1.789
Positive Control Cyclophosphamide 
 0.1       
 50 1050 531 0.506 10.62 26.0 24.941
Cyclophosphamide 
 0.6       
 10 210 237 1.129 23.70 26.0 178.824
Trend: 1.028        
Probability: 0.152