Detection of mutation by ames test

Ames test, its principle , procedure, advantage and applications

1. A SEMINAR PRESENTATION ON : TEST SUBMITTED BY, Sambit Dwibedy M.SC – II

2. CONTENTS Introduction Definition Discovery Test organism for Ames Test 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 AMES TEST 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 ?

7. EXAMPLE :ETHYL METHANE SULPHONATE (EMS)

8. PRINCIPLE TEST SAMPLE Many Reverted wild his ⁺

9. PRINCIPLE CONTROL SAMPLE Few Reverted wild his ⁺ If reverted S.typhimurium of test sample >>control sample Then suspected mutagen is mutagenic Spontaneous mutation

10. METHODS There are 2 main methods of Ames Test: 1. Conventional pour plate method 2. Fluctuation method

11. METHODS CONVENTIONAL POUR PLATE METHOD FLUCTUATION METHOD

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

13. APPLICATIONS Ames Test is widely used by pharmaceutical industry.

14. APPLICATIONS Ames Test is also used in cosmetic industry.

15. APPLICATIONS Ames Test is also widely used in Food Processed Industries.

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

17. CONCLUSION 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. REFERENCES 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.