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Study Information
Study Attribute Value
CEBS Accession Number: 002-02859-0010-0000-7
Chemical Name: Sulfisoxazole
CASRN: 127-69-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 112199
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 Acetone 
 0         
 112 116 67 20 28
    107 89 71 22
    108 99 118 36
    83 97 87 35
Test Chemical Sulfisoxazole 
62.5       
 97 103 84 29 25
    113 102 75 22
    106 107 76 24
  
125         
 111 90 94 28 30
    95 68 89 31
    116 88 108 31
  
250         
 105 84 90 29 29
    111 72 107 32
    111 104 83 25
  
500         
 102 80 116 38 36
    85 37 108 43
    114 75 98 29
  
750         
 63 22 115 61 43*
    105# 70 86 27
    92 39 115 42
  
1000         
 78 12 290 125 82*
    78 25 116 50
    74 13 159 72
Positive Control Methyl Methane Sulfonate 
5         
 94 79 226 80 77*
    84 83 217 86
    75 90 142 63

Nonactivation Trial: 2 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Acetone 
 0         
 90 102 143 53 54
    100 97 186 62
    121r 118 175 48
    98 101 134 46
Test Chemical Sulfisoxazole 
100         
 126r 99 183 48
    120# 119 199 56
    124r 130 176 47
  
200         
 122r 85 186 51
    126r 80 183 48
    128r 104 180 47
  
400         
 69 17 192 93
    126r 54 186 49
    121r 66 280 77
  
600         
 132r 40 116 29 67
    115 22 221 64
    114 69 242 71
Positive Control Methyl Methane Sulfonate 
5         
 35 16 791 757 674*
    61 56 1036 563
    58 52 1220 701

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