Genetic Toxicology - Mammalian Cell Mutagenicity

Study Information
Study Attribute	Value
CEBS Accession Number:	002-01385-0003-0000-2
Chemical Name:	3,3',5,5'-Tetramethylbenzidine
CASRN:	54827-17-7
NTP Study Type:	Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID:	831590
Study Result:	Positive

View Study Details | View Protocol | Download To Excel

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: Inconclusive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Solvent	0	99	110	139	47	51
			86	97	121	47
			95	102	122	43
			84	91	164	65
Test Chemical	3,3',5,5'-Tetramethylbenzidine	15.4	91	82	242	89	79
			78#	62	160	69	79
		30.7	99	98	250	84	79*
			73	74	163	74	79*
		51.2	70	30	278	133	133*
			61	14	243	133	133*
		100	58	18	504	289	208*
			72	33	275	128	208*
		125	67	19	438	217	181*
			74	27	320	144	181*
Positive Control	Ethyl Methane Sulfonate	500	42	36	990	783	617*
			46	39	1125	821
			98	120	726	248

Nonactivation Trial: 2 Experiment Call: Negative
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	58	89	75	43	49
			55	74	111	68
			72#	137	93	43
			58	101	73	42
Test Chemical	3,3',5,5'-Tetramethylbenzidine	42	45	12	96	72	62
			34	10	52	51	62
		53	15	5	40	88	79
			30	6	63	69	79
		66
			25	3	69	91
		82

Positive Control	Ethyl Methane Sulfonate	500	40	50	955	803	843*
			30	29	813	908
			37	41	903	817

Nonactivation Trial: 3 Experiment Call: Negative
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	85	106	54	21	24
			86	81	74	29
			83	116	41	17
			84	97	75	30
Test Chemical	3,3',5,5'-Tetramethylbenzidine	26	64	93	82	43	37*
			89	111	73	27
			74	100	91	41
		33	71	92	68	32	23
			120	163	53	15
			124r	161	116	31
		41	81	98	74	30	32
			76	89	102	45
			85	94	54	21
		51	73	53	101	46	59*
			66	28	151	76
			73	60	118	54
		64


Positive Control	Ethyl Methane Sulfonate	500	59	50	1163	655	702*
			49	45	1110	750
			64	59	1354	702

Induced S9 Trial: 1 Experiment Call: Rejected
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	75	111	47	21	26
			53	77	46	29
			73	112	61	28
Test Chemical	3,3',5,5'-Tetramethylbenzidine	41	78	138	55	24	21
			83	146	48	19	21
		51	89	142	69	26	27
			60	103	52	29	27
		64	72	118	22	10	17
			68	116	47	23	17
		80	68	114	47	23	25
			69	117	56	27	25
		100	72	118	51	24	24
			70	106	53	25	24
		125	60	84	46	26	30
			61	83	64	35	30
Positive Control	3-Methylcholanthrene	5	43	54	217	168	162*
			47	56	247	176
			54	60	230	143

Induced S9 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	100	116	331	110	102
			112	99	399	119
			104	85	236	76
Test Chemical	3,3',5,5'-Tetramethylbenzidine	52	85#	100	225	88	83
			81#	135	163	67
			55	74	155	94
		66	80	79	276	116	85
			80	127	150	62
			78	105	179	76
		82	82	78	212	86	85
			93	99	213	77
			88	81	240	91
		102	86	81	204	79	74
			82	74	172	70
			91	95	199	73
		128	105	90	154	49	54
			118	106	209	59
			97	87	161	55
Positive Control	3-Methylcholanthrene	5	61	33	814	445	460*
			77	38	1002	437
			60	32	900	497

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