Table 3.

Summary of chromosomal aberration test results.

Groups	S9 mix	Treatment time (h)	Harvest time (h)	Mean aberrant cells/150 cells		Number of aberrations
				Incl. gaps	Excl. gaps	Incl. gaps	Excl. gaps
Experiment A1
Test item
500 μg/mL	−	3	20	9	4	9	4
1000 μg/mL	−	3	20	8	4	8	4
2000 μg/mL	−	3	20	9	4	9	4
Vehicle control	−	3	20	8	4	8	4
Positive control	−	3	20	39∗∗	34∗∗	67∗∗	43∗∗
Hist Veh control4	−	3	20	4.70–7.82	1.59–4.11	n/a	n/a
Test item
500 μg/mL	+	3	20	9	4	10	4
1000 μg/mL	+	3	20	9	5	10	6
2000 μg/mL	+	3	20	9	3	9	3
Vehicle control	+	3	20	7	4	8	4
Positive control	+	3	20	51∗∗	44∗∗	86∗∗	63∗∗
Hist Veh control4	+	3	20	4.66–8.12	1.69–4.35	n/a	n/a
Experiment B 2
Test item
500 μg/mL	−	20	20	7	3	8	4
1000 μg/mL	−	20	20	8	5	8	5
2000 μg/mL	−	20	20	7	4	7	4
Vehicle control	−	20	20	7	3	7	3
Positive control	−	20	20	45∗∗	41∗∗	84∗∗	58∗∗
Hist Veh Control4	−	20	20	4.44–7.90	1.60–4.27	n/a	n/a
Experiment B 3
Test item
500 μg/mL	−	20	28	9	4	9	4
1000 μg/mL	−	20	28	9	3	10	3
2000 μg/mL	−	20	28	8	4	8	4
Vehicle control	−	20	28	8	3	8	3
Positive control	−	20	28	45∗∗	41∗∗	78∗∗	53∗∗
Hist Veh control4	−	20	28	4.31–7.77	1.59–4.11	n/a	n/a
Test item
500 μg/mL	+	3	28	8	4	9	4
1000 μg/mL	+	3	28	8	4	9	4
2000 μg/mL	+	3	28	9	4	9	4
Vehicle control	+	3	28	9	3	9	3
Positive control	+	3	28	47∗∗	39∗∗	70∗∗	50∗∗
Hist Veh control4	+	3	28	4.96–7.56	1.92–4.12	n/a	n/a

Abbreviations: n/a: not applicable; Veh: vehicle; Hist: historical; incl: including; excl: excluding; ¹Positive controls: (−S9): Ethyl methanesulfonate (1.0 μL/mL); (+S9): Cyclophosphamide (5.0 μg/mL); ²Positive control: (−S9): Ethyl methanesulfonate (0.4 μL/mL); ³Positive controls: (−S9) Ethyl methanesulfonate (0.4 μL/mL); (+S9): Cyclophosphamide (5.0 μg/mL); ⁴Numbers reported are the 95% confidence interval. ^∗p < 0.05; ^∗∗p < 0.01, to the concurrent vehicle control and to the historical vehicle control.