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Study Information
Study Attribute Value
CEBS Accession Number: 002-02464-0002-0000-0
Chemical Name: Methylene blue trihydrate
CASRN: 7220-79-3
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 563848_CA
Study Result: Positive

Study Result: Positive
Activation Trial Trial Call
No Activation  1  Positive 
Induced Rat Liver S9  1_S9  Weakly Positive* 
No Activation  2  Positive 

Trial #:1   Activation: No Activation    Date: 05/07/1991    Harvest Time: 13.7 hour(s)   Trial Call: Positive   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Water 
0         
 200 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Methylene blue trihydrate 
7.5       
 200 6 0.030 3.0 2 0.010 1.0 4 0.020 2.0 0 0.000 0.0 
10         
 200 8 0.040 4.0 2 0.010 1.0 6 0.030 3.0 0 0.000 0.0 
15         
 200 14 0.070 7.0 6 0.030 3.0 8 0.040 3.0 0 0.000 0.0 
25         
 50 30 0.600 34.0 14 0.280 16.0 16 0.320 24.0 0 0.000 0.0 
35         
 0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.4       
 25 17 0.680 52.0 13 0.520 44.0 4 0.160 16.0 0 0.000 0.0
Trend: 7.715 5.518 6.076  
Probability: 0.000 0.000 0.000  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 03/26/1991    Harvest Time: 13.5 hour(s)   Trial Call: Weakly Positive*   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Water 
0         
 200 3 0.015 1.5 3 0.015 1.5 0 0.000 0.0 0 0.000 0.0
Test Chemical: Methylene blue trihydrate 
1         
 200 3 0.015 1.5 0 0.000 0.0 3 0.015 1.5 0 0.000 0.0 
2.2       
 200 5 0.025 2.5 3 0.015 1.5 2 0.010 1.0 0 0.000 0.0 
4.7       
 200 42 0.210 12.0 20 0.100 7.5 12 0.060 5.5 10 0.050 0.5 
10         
 0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
20         
 25 12 0.480 24.0 5 0.200 16.0 7 0.280 20.0 0 0.000 0.0
Trend: 5.009 3.847 3.600  
Probability: 0.000 0.000 0.000  


Trial #:2   Activation: No Activation    Date: 03/26/1991    Harvest Time: 13.7 hour(s)   Trial Call: Positive   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Water 
0         
 200 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Methylene blue trihydrate 
4.7       
 200 3 0.015 0.5 1 0.005 0.5 2 0.010 0.5 0 0.000 0.0 
10         
 200 5 0.025 2.5 2 0.010 1.0 3 0.015 1.5 0 0.000 0.0 
22         
 200 50 0.250 18.5 32 0.160 13.0 18 0.090 8.0 0 0.000 0.0 
47         
 0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 
100         
 0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.4       
 25 18 0.720 48.0 9 0.360 28.0 9 0.360 32.0 0 0.000 0.0
Trend: 8.106 6.724 5.088  
Probability: 0.000 0.000 0.000