Genetic Toxicology - Mammalian Cell Mutagenicity

Study Information
Study Attribute	Value
CEBS Accession Number:	002-01563-0001-0000-8
Chemical Name:	7-Bromomethyl-12-methylbenz(a)anthracene
CASRN:	16238-56-5
NTP Study Type:	Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID:	G13405
Study Result:	Positive

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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	82	97	130	53	46
Vehicle Control			61	108	70	38	46
Test Chemical	7-Bromomethyl-12-methylbenz(a)anthracene	0.188	44	70	117	89	85*
			47#	79	114	81	85*
		0.375	57	66	165	96	155*
			30	42	191	213	155*
		0.75	54	61	193	119	139*
			50	61	236	158	139*
		1.5	40#	18	516	428	457*
			18#	11	255	486	457*
		3	4r	0	44	367
			28	15	232	280
Positive Control	Ethyl Methane Sulfonate	500	26	16	1070	1354	1241*
Positive Control			26	26	896	1127	1241*
Negative Control	Negative (Not Specified)	0	76#	102	103.5	46	50*
Negative Control			60#	93	98	54	50*

Nonactivation Trial: 3 Experiment Call: No Call
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	106	118	68	21	21
			112	82	70	21
			126r	113	77	20
			122r	118	71	19
Test Chemical	7-Bromomethyl-12-methylbenz(a)anthracene	0.094	113	133	88	26	24
			118	115	81	23	24
		0.187	102	125	86	28	29
			105#	117	93	30	29
		0.375	98	120	104	35
			128r	92	150	39
		0.75	122r	112	171	47
			136r	122	169	41
		1.5	113	104	230	68	68*
			91	107	186	68	68*
		3	102	88	363	118	126*
			101	50	407	134	126*
Positive Control	Ethyl Methane Sulfonate	500	44	38	772	587	620*
Positive Control			65	25	1278	654	620*

Nonactivation 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	92	128	53	19	21
			89	106	62	23
			83	66	50	20
Test Chemical	7-Bromomethyl-12-methylbenz(a)anthracene	0.5

		1	84	75	143	57	52*
			88	108	126	48	52*
		2	96	66	248	86	72*
			90	78	156	58	72*
		3	81	65	210	87	105*
			66	38	244	124	105*
		4	64	34	264	137	147*
			61	41	289	158	147*
Positive Control	Ethyl Methane Sulfonate	500	35	23	801	767	713*
			42	32	825	650
			40	22	857	723

Non-Induced S9 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	111	95	150	45	46
Vehicle Control			113	105	160	47	46
Test Chemical	7-Bromomethyl-12-methylbenz(a)anthracene	0.75	114	113	431	126	134*
			89	60	381	142	134*
		1.5	98	46	456	155	177*
			70	63	416	198	177*
		3	77	44	437	189	240*
			60	43	519	290	240*
		4.5	63	38	522	278	235*
			82	41	475	193	235*
		6	49	13	549	371	280*
			93	57	524	188	280*
Positive Control	3-Methylcholanthrene	5	68	20	469	231	223*
Positive Control			94	40	607	215	223*
Negative Control	Negative (Not Specified)	0	120r	176	143	40
Negative Control			138r	192	177	43

Induced S9 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	67	89	63	31	35
Vehicle Control			79	99	91	39	35
Test Chemical	7-Bromomethyl-12-methylbenz(a)anthracene	0.375	66	94	132	67	65*
			85	99	161	63	65*
		0.75	75	101	228	102	111*
			66	96	238	120	111*
		1.5	62	77	336	180	170*
			75	78	358	160	170*
		3	71	31	638	299	384*
			43	25	601	470	384*
		6

Positive Control	3-Methylcholanthrene	5	42	16	412	328	301*
Positive Control			61	10	499	274	301*
Negative Control	Negative (Not Specified)	0	80	93	95	40	38*
Negative Control			102	119	112	37	38*

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	85	89	377	148	133
Vehicle Control			81	107	289	119	133
Test Chemical	7-Bromomethyl-12-methylbenz(a)anthracene	0.188	70	63	527	253	215*
			67	108	355	177	215*
		0.375	70	91	447	212	222*
			93	89	642	231	222*
		0.75	58	61	567	323	369*
			62	56	770	414	369*
		1.5	62	44	798	428	431*
			43	39	561	435	431*
		3

Positive Control	3-Methylcholanthrene	5
Positive Control
Negative Control	Negative (Not Specified)	0	77#	73	445.5	192	137*
Negative Control			74	131	183	82	137*

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