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Study Information
Study Attribute Value
CEBS Accession Number: 002-01515-0012-0000-7
Chemical Name: 4-Nitro-o-phenylenediamine
CASRN: 99-56-9
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: G31547
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: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 101 107 52 17 21
    80 89 55 23
    82 97 55 22
    100 107 65 22
Test Chemical 4-Nitro-o-phenylenediamine 
75         
 89 73 83 31 33
    92 74 95 35
  
150         
 95 56 140 49 50*
    93 47 139 50
  
225         
 73 39 149 68 64*
    90 39 163 60
  
300         
 94# 27 186 66 68*
    88 25 186 70
  
450         
 72 9 160 74 81*
    65 5 173 89
Positive Control Ethyl Methane Sulfonate 
500         
 51 30 681 447 455*
    50 33 698 464

Nonactivation 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         
 49r 125 36 24 20
    51 106 39 26
    65 104 39 20
    61 90 26 14
Test Chemical 4-Nitro-o-phenylenediamine 
75         
 66 47 98 49 55*
    61 46 109 60
  
150         
 63 39 146 78 81*
    65 62 163 84
  
250         
 63 29 265 141 132*
    60 31 220 123
  
300         
 43 22 175 135 105*
    25 6 57 75
  
318.8       
 54 37 201 124 114*
    54 24 167 103
Positive Control Ethyl Methane Sulfonate 
500         
 38 56 649 567 631*
    32 29 671 695

Nonactivation Trial: 3 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 72 88 53 25 25
    76 92 57 25
    80 93 61 26
    99 127 74 25
Test Chemical 4-Nitro-o-phenylenediamine 
150         
 74 42 123 55 55*
    53 34 88 55
  
250         
 92 52 148 54 67*
    59 41 143 81
  
300         
 81 30 196 81 82*
    67 28 166 83
  
375         
 59 21 166 94 98*
    62# 16 187.5 101
  
425         
 34 4 80 78 105*
    47 8 188 132
  
500         
 33 3 78 80 81*
    37 5 91 82
Positive Control Ethyl Methane Sulfonate 
500         
 39 32 758 653 620*
    36 43 606 559
    39 45 750 649

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         
 100 124 85 28 31
    102 107 110 36
    115 100 94 27
    67 68 64 32
Test Chemical 4-Nitro-o-phenylenediamine 
12.5       
 105 23 113 36 43
    82 21 122 49
  
25         
 64 12 102 53 51
    75 12 111 49
  
50         
 82 11 112 46 49
    71 9 113 53
  
100         
 66 8 177 89 70*
    95 12 146 51
  
150         
   
Positive Control 3-Methylcholanthrene 
5         
 62 39 677 362 297*
    84 46 589 233

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         
 56 113 68 41 51
    61 89 116 63
    60 98 86 48
    50r 103 79 53
Test Chemical 4-Nitro-o-phenylenediamine 
15         
 73 56 176 81 69
    61 74 126 69
    65 77 112 57
  
30         
 64 42 191 99 81*
    64 74 143 75
    80 80 168 70
  
60         
 55 51 175 106 103*
    60 64 137 77
    61 46 229 125
  
100         
 54 38 159 99 111*
    53 44 159 99
    69 35 279 136
  
120         
 52 51 138 89 95*
    49 29 120 82
    52 41 177 114
Positive Control 3-Methylcholanthrene 
5         
 40 32 481 403 392*
    36 17 432 404
    40 29 440 370

Induced S9 Trial: 3 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 105 93 74 24 21
    93 102 50 18
    103 101 71 23
    79 104 50 21
Test Chemical 4-Nitro-o-phenylenediamine 
20         
 88 39 87 33 38*
    102 34 130 43
    78 38 87 37
  
40         
 88 31 137 52 53*
    95 33 150 53
    89 29 145 54
  
80         
 76 23 138 60 65*
    99 23 179 60
    103 22 229 74
  
100         
 75 19 172 76 77*
    84 14 221 88
    99 20 197 67
  
150         
 88 16 172 65 83*
    67 9 195 97
    88 11 227 86
  
200         
 88 15 180 68 70*
    86 9 178 69
    72 8 160 74
Positive Control 3-Methylcholanthrene 
5         
 67 33 461 228 205*
    68 40 454 221
    91 53 452 166

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