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: 002-01934-0010-0000-0
Chemical Name: Cytembena
CASRN: 21739-91-3
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 644192
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         
 88 105 102 39 47
    100 92 131 44
    107 103 154 48
    104 100 184 59
Test Chemical Cytembena 
6.25      
 110 104 125 38 41
    108 92 141 43
  
12.5       
 139r 104 164 39
    104 91 133 42
  
25         
 92 74 148 54 51
    91 85 133 49
  
50         
 89 59 307 115 109*
    93 51 288 103
  
100         
 25 2 335 441 452*
    26 4 368 463
Positive Control Methyl Methane Sulfonate 
15         
 68 40 408 200 202*
    56 37 343 203
Methyl Methane Sulfonate 
250         
 78 59 525 225 199*
    79 71 407 173

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         
 65 91 93 48 50
    83 101 113 45
    81 104 128 53
    80 104 133 55
Test Chemical Cytembena 
25         
 67 59 227 114 134*
    63 57 291 154
  
50         
 43 16 617 478 464*
    49 17 656 449
  
75         
 19 2 349 618 603*
    21 3 368 589
  
100         
   
Positive Control Methyl Methane Sulfonate 
15         
 34 25 256 255 233*
    35 25 223 211
Methyl Methane Sulfonate 
250         
 60 77 365 204 224*
    63 72 461 243

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