Genetic Toxicology - Mammalian Cell Mutagenicity

Study Information
Study Attribute	Value
CEBS Accession Number:	002-01687-0001-0000-5
Chemical Name:	Benz(a)anthracene
CASRN:	56-55-3
NTP Study Type:	Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID:	G16554
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: No Call
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	105	86	31	10	13
Vehicle Control			106	130	54	17	13
Test Chemical	Benz(a)anthracene	15.6	70	35	63	30	24*
			79	47	43	18	24*
		31.3	61	37	74	41	31*
			62	59	39	21	31*
		62.5	65	35	45	23	23
			63	52	45	24	23
		125	66	44	48	24	24*
			66	27	48	24	24*
		250	71	23	57	27	23
			79	28	47	20	23
Positive Control	Ethyl Methane Sulfonate	500	35#	10	751.5	716	693*
Positive Control			37#	8	738	671	693*
Negative Control	Negative (Not Specified)	0	89#	97	33	12	19*
Negative Control			95	87	71	25	19*

Nonactivation Trial: 2 Experiment Call: Negative and Non-Toxic
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	62	94	46	25	21
Vehicle Control			85	92	45	18	21
Test Chemical	Benz(a)anthracene	31.3	64	73	52	27	28
			75	104	64	29	28
		62.5	75	64	64	29	34
			59	61	68	39	34
		125	76	65	74	32	30
			104	73	83	27	30
		250	77	31	92	40	40*
			66	32	78	40	40*
		500	59	10	66	37	37*
			59	11	66	37	37*
		750

Positive Control	Ethyl Methane Sulfonate	500	38	28	814	717	804*
Positive Control			32	23	851	891	804*
Negative Control	Negative (Not Specified)	0	110	112	68	21	23*
Negative Control			91	101	67	24	23*

Nonactivation Trial: 3 Experiment Call: Negative and Non-Toxic
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	89	109	55	21	20
			96	82	54	19
			101	109	61	20
Test Chemical	Benz(a)anthracene	31.3	90	61	70	26	28
			75	64	66	29
			84	58	72	29
		62.5	91	59	48	18	18
			79	53	53	23
			79	55	34	14
		125	81	40	74	31	24
			104	52	57	18
			114	55	81	24
		250	72	30	69	32	29
			78	28	61	26
			65	28	56	29
		500	66	13	62	31	29
			62	10	50	27
			80	7	70	29
Positive Control	Ethyl Methane Sulfonate	500	45	21	1024	753	834*
			37	16	994	895
			33	13	849	853

Induced S9 Trial: 1 Experiment Call: No Call
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	77	73	116	50	40
Vehicle Control			109	118	97	30	40
Test Chemical	Benz(a)anthracene	0.122	93	48	139	50	47
			96	52	128	45	47
		0.244	108	54	135	42	55
			76	36	154	68	55
		0.488	83	44	156	62	58
			84	26	136	54	58
		0.977	69	30	174	84	87*
			77#	50	207	89	87*
		1.95	98	23	385	131	229*
			44	14	428	327	229*
		3.91

Positive Control	3-Methylcholanthrene	5	57	12	512	299	310*
Positive Control			50	9	485	321	310*
Negative Control	Negative (Not Specified)	0	81	109	99	41
Negative Control			126r	93	121	32

Induced S9 Trial: 2 Experiment Call: No Call
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	67	80	74	37	39
Vehicle Control			81	115	102	42	39
Test Chemical	Benz(a)anthracene	0.5	85	91	93	36	37
			86	116	99	39	37
		1	80	99	81	34	34
			85	95	88	34	34
		2	83	132	116	47	47
			77	108	109	47	47
		3	84	116	100	40	37
			65	100	65	34	37
		4	55	42	206	124	105*
			73	61	186	86	105*
Positive Control	3-Methylcholanthrene	5	29	12	279	323	339*
Positive Control			23	12	249	356	339*
Negative Control	Negative (Not Specified)	0	74	94	79	35	36*
Negative Control			89	111	95	36	36*

Induced S9 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	86	74	80	31	27
Vehicle Control			92	116	64	23	27
Test Chemical	Benz(a)anthracene	0.25	88	47	91	35	41
			82	65	116	47	41
		0.5	99	61	144	49	47*
			97	56	130	45	47*
		1	93	36	157	56	54*
			120	42	188	52	54*
		2

Positive Control	3-Methylcholanthrene	5	39	12	231	200	221*
Positive Control			45	14	329	242	221*
Negative Control	Negative (Not Specified)	0	79	87	92	39	33*
Negative Control			100	123	81	27	33*

Induced S9 Trial: 4 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	54	101	80	50	50
			62	115	104	56
			66	89	113	57
			65	95	72	37
Test Chemical	Benz(a)anthracene	0.25	90	171	52	19	26
			84	143	84	33	26
		0.5	42	36	85	67	50
			70	111	69	33	50
		1	77	83	126	55	48
			78	113	95	41	48
		2	69	57	229	110	102*
			110	89	240	73
			64	68	235	123
		3	73	50	342	157	177*
			83	37	402	162
			56	23	353	211
		4	57	9	456	265	242*
			47	5	427	304
			65	36	307	158
		6


Positive Control	3-Methylcholanthrene	5	37	14	625	558	497*
			48	32	572	400
			39	20	616	533

Induced S9 Trial: 5 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	126r	87	156	41	40
			122r	110	163	44
			112#	109	117	35
			112	91	150	45
Test Chemical	Benz(a)anthracene	0.25	103	60	94	30	27
			96#	96	63	22
			87	94	77	30
		0.5	112	80	76	23	45
			84	54	180	71
			96	78	115	40
		1	100	69	193	64	53
			100	93	111	37
			114#	71	200	59
		2	79	11	236	100	93*
			84	50	245	98
			105	44	261	83
		3

			121r	48	323	89
		4


Positive Control	3-Methylcholanthrene	2.5	92	43	543	196	208*
Positive Control			103	41	679	220	208*

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