Government Funding Lapse

Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted. The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit  cc.nih.gov. Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Study Information
Study Attribute Value
CEBS Accession Number: 002-02785-0009-0000-3
Chemical Name: Roxarsone
CASRN: 121-19-7
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 941114
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: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 83# 99 74 30 33
    78 106 77 33
    75 89 91 40
    70 106 57 27
Test Chemical Roxarsone 
125         
 57 99 107 63 42
    102 150 74 24
    68 96 76 37
  
250         
 67 102 70 35 30
    58 76 53 30
    73 113 53 24
  
500         
 83 111 73 29 25
    71 101 48 23
    78 79 56 24
  
750         
 67 36 87 43 35
    88 76 89 34
    86 91 76 29
  
1000         
 85 40 99 39 34
    91# 47 86 32
    72 56 67 31
  
1500         
   
   
Positive Control Methyl Methane Sulfonate 
5         
 55 54 424 259 211*
    77 56 429 185
    78 59 442 188

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         
 88 103 72 27 26
    83 95 66 26
    76 103 52 23
    94 99 74 26
Test Chemical Roxarsone 
400         
 80 77 72 30 35
    70 82 82 39
    64 85 66 35
  
500         
 74 62 59 26 26
    76 70 54 24
    89 76 71 26
  
600         
 56 45 47 28 27
    70 59 45 21
    72 65 69 32
  
800         
 56 28 60 36 35
    70 32 68 32
    58 29 63 36
  
1000         
 38# 11 62 54 45*
    54 16 72 45
    67 29 75 37
  
1200         
 60# 12 88 49 74*
    35 7 80 77
    38 7 110 96
  
1500         
   
   
Positive Control Methyl Methane Sulfonate 
5         
 28 19 253 305 260*
    40 23 257 217
    33 20 252 257

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         
 88 128 61 23 30
    64 86 69 36
    72 104 67 31
    67 82 64 32
Test Chemical Roxarsone 
400         
 75 61 95 42 36
    61 73 45 25
    55 66 66 40
  
500         
 61 47 73 40 41
    61 59 84 46
    46 54 53 38
  
600         
 52 52 62 40 44
    58 47 56 32
    58 30 102 59
  
800         
 66 44 77 39 48*
    47 25 76 54
    56 32 87 52
  
1000         
 73 22 140 64 71*
    63 19 132 69
    56 10 136 81
  
1200         
   
   
Positive Control Methyl Methane Sulfonate 
5         
 34 40 316 313 304*
    24 29 265 373
    39 47 265 226

Induced S9 Trial: 1 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 65 103 58 30 28
    69 84 40 19
    80 119 67 28
    60 94 62 34
Test Chemical Roxarsone 
125         
 26 54 70 90 63*
    52 77 68 44
    44 80 75 57
  
250         
 46 71 82 59 55*
    38 37 59 52
    35 49 57 54
  
500         
 35 41 104 100 75*
    49 65 66 45
    43 41 101 79
  
750         
 66 38 135 68 85*
    44 19 88 67
    34 12 121 119
  
1000         
   
   
Positive Control 3-Methylcholanthrene 
2.5       
 27 25 408 501 642*
    25 30 388 521
    14 14 389 905

Induced S9 Trial: 2 Experiment Call: Rejected
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 102 81 184 60 37
    117 116 101 29
    129r 94 137 35
    107 102 68 21
Test Chemical Roxarsone 
500         
 94 55 83 29 35
    99 63 108 36
    67 48 78 39
  
700         
 116 60 96 28 26
    121r 46 95 26
    91 66 69 25
  
800         
 90 39 115 42 49
    38 18 71 63
    104 53 133 43
  
900         
 87 18 159 61 47
    106 26 146 46
    91 46 90 33
  
1000         
 135r 62 130 32 28
    114 53 96 28
    112 58 94 28
  
1250         
   
   
Positive Control 3-Methylcholanthrene 
2.5       
 121r 57 402 111 112*
    126r 59 497 132
    109 75 363 112

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