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Study Information
Study Attribute Value
CEBS Accession Number: 002-02941-0011-0000-0
Chemical Name: Trichlorfon
CASRN: 52-68-6
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 383555
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         
 90 117 95 35 36
    96 107 96 33
    81 88 90 37
    71 89 80 38
Test Chemical Trichlorfon 
31.25      
 91 106 89 32 35
    104 94 118 38
  
62.5       
 75 99 78 35 34
    99 115 102 34
  
125         
 94 104 113 40 46
    82 80 127 52
  
250         
 83 43 356 143 144*
    75 47 329 146
  
500         
 42 7 498 397 367*
    54 7 549 337
Positive Control Methyl Methane Sulfonate 
15         
 40 18 424 350 386*
    31 14 397 422

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         
 61 81 82 45 38
    82 100 91 37
    96 111 69 24
    72 108 100 46
Test Chemical Trichlorfon 
200         
 94 65 370 131 170*
    72 41 448 209
  
300         
 59 20 533 301 299*
    52 15 458 296
  
500         
 22 3 204 307 294*
    29 5 246 281
  
600         
 11 1 448 1378 1062*
    19 3 418 746
Positive Control Methyl Methane Sulfonate 
15         
 31 28 162 172 150*
    44 38 168 128

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