['   ', ' ', 'VIII..', 'INTERPRETATION', 'OF', 'RESULTS:', '(continued)', 'In', 'the', 'presence', 'of', 'metabolic', 'activation,', 'the', 'test', 'material', 'was', 'also.', 'assayed', 'from', '0.25', 'pl', '/ml', 'to', '10.0', 'p1/ml', 'andi,', 'at.', 'most,', 'low', 'toxicities', 'were', 'induced', '(percent', 'relative', 'growths,', '111.5%', 'to:', '80.', '6%).', 'Again,', 'there', 'was', 'no', 'evidence', 'for', 'mtagenic', 'activity.', 'The', 'minimum', 'criterion', 'for', 'mtage-', 'nesis', 'in', 'this', 'assay', 'was', 'a', 'mutant.', 'frequency', 'exceeding', '79.3x10-6', 'and', 'the', 'assayed', 'treatments.', 'induced', 'mutant', 'frequencies', 'ranging', 'from', '12.8x10-&', 'to', '56.1', 'x', '10-6,', 'The', 'test', 'material', 'was', 'therefore', 'considered', 'nonmutageniic', 'with', 'activation', 'up', 'to', 'the', 'testing', 'limit', 'of', '10', 'ul/ml.', 'Im', 'the', 'assays', 'used', 'in', 'this', 'evaluation,', 'the', 'average', 'cloning', 'efficiencies', 'for', 'the', 'solvent', 'and', 'untreated', 'negative:', 'controls.', 'varied', 'from', '64.0%.', 'with-', 'out', 'activation', 'to', '59.3%', 'with', 'activation', 'which', 'demonstrated', 'acceptable', 'cloning', 'conditions', 'for', 'the', 'assays.', 'The', 'negative', 'control', 'mutant', 'fre-', 'quencies.', 'were', 'a7]', 'in', 'the', 'normal', 'range', 'andi', 'the:', 'positive', 'control', 'compounds', 'yielded', 'nonmal', 'mutant', 'frequencies', 'that.', 'were', 'greatly', 'in.', 'excess', 'of', 'the', 'background.', 'IX,', 'CONCLUSIONS:', 'The', 'test.', 'material,', 'B122,', 'did', 'not.', 'induce', 'significant', 'increases', 'in', 'the', 'mutant', 'frequency', 'at', 'the', 'TK', 'locus', 'jim', 'L5168Y', 'mouse', 'lymphoma', 'cells.', 'With', 'and', 'without.', 'metabolic', 'activation', 'concentrations.', 'from', '0.25', '»l/ml', 'to', '10.0', 'pl/ml', 'were', 'assayed', 'for', 'mutant', 'induction', 'without.', 'inducing', 'significant', 'increases', 'above', 'the', 'background', 'mutant', 'frequency', '(average', 'of', 'solvent', 'and', 'untreated', 'controls}.', 'At', 'most,', 'moderate', 'toxicities', 'were', 'observed', 'but', 'the', 'testing', 'limit', 'of', '10', 'yl/ml', 'was', 'reached.', 'The', 'test', 'material', 'is', 'there-', 'fore:', 'considered', 'inactive', 'in', 'the', 'Mouse', 'Lymphoma', 'Forward', 'Mutation', 'Assay', 'with', 'and', 'without', 'metabolic', 'activation:', 'at', 'moderate', 'toxicities.', ' ', 'SUBMITTED.', 'BY:', 'Study', 'Director', 'Mya.', 'Via', 'Peep', '.', 'lath', 'a}', 'Maria', 'A.', 'Cifone,', 'Ph.D...', 'Date', 'Cell', 'Biologist', 'Department', 'of', 'Molecular', 'Toxicology', 'REVIEWED:', 'BY:', '=', '¢', 'SO9zEerEs', ' ', 'Bue', 'C.', 'Hd', 'sh', '6/3', 'fp', '“David', 'J.', 'Brusick,', 'PhO,', '"', 'Date', 'Director', 'Department', 'of', 'Molecular', 'Toxicology', '[8', 'BIONETICS', 'Litton', '  ', '  ', 'i', '2']