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Study Information
Study Attribute Value
CEBS Accession Number: 002-01563-0001-0000-8
Chemical Name: 7-Bromomethyl-12-methylbenz(a)anthracene
CASRN: 16238-56-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: G13405
Study Result: Positive


Table Instructions and Notes:
Studies are indicated to be "Nontoxic" when the observed reductions in relative total growth did not indicate that the maximum tolerated dose was achieved.

Nonactivation Trial: 1 Experiment Call: No Call
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 82 97 130 53 46
    61 108 70 38
Test Chemical 7-Bromomethyl-12-methylbenz(a)anthracene 
 0.188     
 44 70 117 89 85*
    47# 79 114 81
  
 0.375     
 57 66 165 96 155*
    30 42 191 213
  
 0.75      
 54 61 193 119 139*
    50 61 236 158
  
1.5       
 40# 18 516 428 457*
    18# 11 255 486
  
3         
 4r 0 44 367
    28 15 232 280
Positive Control Ethyl Methane Sulfonate 
500         
 26 16 1070 1354 1241*
    26 26 896 1127
Negative Control Negative (Not Specified) 
 0         
 76# 102 103.5 46 50*
    60# 93 98 54

Nonactivation Trial: 3 Experiment Call: No Call
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 106 118 68 21 21
    112 82 70 21
    126r 113 77 20
    122r 118 71 19
Test Chemical 7-Bromomethyl-12-methylbenz(a)anthracene 
 0.094     
 113 133 88 26 24
    118 115 81 23
  
 0.187     
 102 125 86 28 29
    105# 117 93 30
  
 0.375     
 98 120 104 35
    128r 92 150 39
  
 0.75      
 122r 112 171 47
    136r 122 169 41
  
1.5       
 113 104 230 68 68*
    91 107 186 68
  
3         
 102 88 363 118 126*
    101 50 407 134
Positive Control Ethyl Methane Sulfonate 
500         
 44 38 772 587 620*
    65 25 1278 654

Nonactivation Trial: 4 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 92 128 53 19 21
    89 106 62 23
    83 66 50 20
Test Chemical 7-Bromomethyl-12-methylbenz(a)anthracene 
 0.5       
   
  
1         
 84 75 143 57 52*
    88 108 126 48
  
2         
 96 66 248 86 72*
    90 78 156 58
  
3         
 81 65 210 87 105*
    66 38 244 124
  
4         
 64 34 264 137 147*
    61 41 289 158
Positive Control Ethyl Methane Sulfonate 
500         
 35 23 801 767 713*
    42 32 825 650
    40 22 857 723

Non-Induced S9 Trial: 1 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 111 95 150 45 46
    113 105 160 47
Test Chemical 7-Bromomethyl-12-methylbenz(a)anthracene 
 0.75      
 114 113 431 126 134*
    89 60 381 142
  
1.5       
 98 46 456 155 177*
    70 63 416 198
  
3         
 77 44 437 189 240*
    60 43 519 290
  
4.5       
 63 38 522 278 235*
    82 41 475 193
  
6         
 49 13 549 371 280*
    93 57 524 188
Positive Control 3-Methylcholanthrene 
5         
 68 20 469 231 223*
    94 40 607 215
Negative Control Negative (Not Specified) 
 0         
 120r 176 143 40
    138r 192 177 43

Induced S9 Trial: 1 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 67 89 63 31 35
    79 99 91 39
Test Chemical 7-Bromomethyl-12-methylbenz(a)anthracene 
 0.375     
 66 94 132 67 65*
    85 99 161 63
  
 0.75      
 75 101 228 102 111*
    66 96 238 120
  
1.5       
 62 77 336 180 170*
    75 78 358 160
  
3         
 71 31 638 299 384*
    43 25 601 470
  
6         
   
Positive Control 3-Methylcholanthrene 
5         
 42 16 412 328 301*
    61 10 499 274
Negative Control Negative (Not Specified) 
 0         
 80 93 95 40 38*
    102 119 112 37

Induced S9 Trial: 2 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 85 89 377 148 133
    81 107 289 119
Test Chemical 7-Bromomethyl-12-methylbenz(a)anthracene 
 0.188     
 70 63 527 253 215*
    67 108 355 177
  
 0.375     
 70 91 447 212 222*
    93 89 642 231
  
 0.75      
 58 61 567 323 369*
    62 56 770 414
  
1.5       
 62 44 798 428 431*
    43 39 561 435
  
3         
   
Positive Control 3-Methylcholanthrene 
5         
   
Negative Control Negative (Not Specified) 
 0         
 77# 73 445.5 192 137*
    74 131 183 82

Footnotes:
Asterisks(*) indicate significant responses.
r = rejected value due to quality control criteria
# = reduced sample size because of the loss of one culture dish due to contamination