The document summarizes the Ames test, which is used to assess the mutagenic potential of chemical compounds. It uses Salmonella typhimurium bacteria as a test organism to detect mutations caused by exposure to test chemicals. If the test chemical causes more reversed his+ bacteria compared to unexposed controls, then it is considered mutagenic. The Ames test is widely used in pharmaceutical, cosmetic, and food industries to screen for potentially carcinogenic chemicals. Though not 100% accurate, it is a simple, inexpensive, and effective way to identify many mutagenic and carcinogenic compounds.

1. TEST
SUBMITTED BY,
Sambit Dwibedy
M.SC – II

2.  Introduction
 Definition
 Discovery
 Test organism for AmesTest
 Mutagen
 Example of mutagen
 Principle
 Methods ; Conventional pour plate and fluctuation
method
 Limitations
 Applications
 Significance
 Conclusion

3. INTRODUCTION

4. WHAT IS AMES TEST ?
Ames test is performed for testing the mutagenic property
of a chemical using bacteria as a test organism.
It is a biological assay to assess the mutagenic potential of
chemical compounds.
DISCOVERY
Ames test was discovered by Bruce
Ames and his group in 1974 at
University of California , Berkeley.

5. TEST ORGANISM
OF AMESTEST
His ⁻ Salmonella
typhimurium is
used.
These mutants
are auxotrophic.
Salmonella typhimurium

6. It is a physical or
chemical agent that
changes DNA of an
organism and
increases the
frequency of
mutations.
Most mutagens are
carcinogens.
WHAT IS MUTAGEN ?

8.  TEST SAMPLE
Hisˉ
S.typhimuriu
m
Suspected
Mutagen
Incubation
Many
Reverted
wild his⁺

9.  CONTROL SAMPLE
Hisˉ
S.typhimuriu
m
No
Suspected
Mutagen
Incubation
Few
Reverted
wild his⁺
If reverted S.typhimurium of test sample >>control sample
Then suspected mutagen is mutagenic
Spontaneous
mutation

10.  There are 2 main methods of AmesTest:
1. Conventional pour plate method
2. Fluctuation method

11. CONVENTIONAL POUR PLATE
METHOD
FLUCTUATION METHOD

12.  S.typhimurium is a prokaryote,therefore it is
not perfect model for human.
 Drugs that contain the nitrate moiety,
sometimes come back +ve for AmesTest
when they are indeed safe.
 It does not give 100% accuracy.

13.  AmesTest is widely used by pharmaceutical
industry.

14.  AmesTest is also used in cosmetic industry.

15.  AmesTest is also widely used in Food
Processed Industries.

16.  It is easy to understand
 Less expensive
 Less time taking
 Easy to handle
 Its is simple

17.  Though Ames test is not 100% accurate but
still it helps us to get rid of 100s of mutagenic
compounds which can cause dreadful disease
like cancer.
 By using many new emerging techniques
efficiency of Ames test can be improved.

18.  1. N.F. Cariello, W.W. Piegorsch,The Ames test: the two-
foldrule revisited, Mutant. Res. 369 (1996) 23–31.
 2. B.N. Ames,W.E. Durston, E.Yamasaki, F.D.
Lee,Carcinogens are mutagens: a simple test system
combiningliver homogenates for activation and bacteria for
detection,Proc. Natl. Acad. Sci. U.S.A. 70 (1973) 2281–2285.
 3. A. Araki,T. Noguchi, F. Kato,T. Matsushima, Improved
method for mutagenicity testing of gaseous compounds by
using a gas sampling bag, Mutat. Res. 307 (1994) 335–344.