AMES TEST By: Harjot Kaur Mentors: Dr. Mahesh Lakshman and Dr. Padmanav Pradhan Location: The City College of New York

ABSTRACT The goal of my project is to evaluate the mutagenicity of the derivatives of common nucleosides. The derivatives of deoxy- and oxy-ribose nucleosides of adenosine and inosine are produced synthetically and purified by chromatography. Then we are going to test these derivatives for carcinogenic and mutagenic activities, by conducting an Ames Test. But before I started this test, I had to do trial Ames Test on control compounds: Adenosine, Inosine, Deoxyadenosine, and Deoxyinosine.

COMPOUNDS

INTRODUCTION In the 1970s a scientist named, Bruce Ames, discovered a procedure that tests carcinogens in compounds. This procedure became to be known as the Ames Test. Studies show that carcinogens are easily detectable in microorganisms. Therefore, a bacterium Salmonella typhimurium was used. This organism cannot survive without the amino acid histidine.

INTRODUCTION(continued) In the procedure, the bacteria were given very little histidine in order to detect its mutation ability. This mutation ability tells us if the compound given to the bacteria is carcinogenic. If the Salmonella mutates, then the compound is carcinogenic. If the Salmonella does not mutates, then the compound is not carcinogenic.

PURPOSE Nucleosides are known to have medicine values. Therefore we are screening these compounds for carcinogenic activities because we want to know if they cause cancer.

MATERIALS AND METHOD Media 1 - Davis Minimal Broth without dextrose: 10.6g - Distilled water: 500mL Media 2 - Nutrient: 200mg - Glucose: 2g - Agar: 15g - Distilled Water: 500mL

MATERIALS AND METHOD 1)Heat Media 2 on a hot plate using a magnetic needle until it changes to a yellowish, light brown color. 2)Sterilized Media 1 and 2 for 20 minutes using an auto clave. 3)Mix Media 1 and 2 in a flask. 4)Cool for 15 minutes. 5)Pour the food (medias) in agar plates. 6)Soak bacteria in salt solution and pour a drop of bacteria on each agar plate.

MATERIALS AND METHOD 7) Heat glass rod after dipping in alcohol. 8) Place agar plates onto rotating plate and spread the bacteria using the heated glass rod. 9) Place 2 sterile paper discs onto the agar plates. 10) Label as desired: Control, A, I, DA, DI. 11) Place a couple of drops of the chemicals to its corresponding paper discs. 12) Rest for 30 minutes. Then incubate for 48 hours under 37ºC.

AFTER 48 HOURS Control: 4 major colonies Adenosine: 4 major colonies; larger, compared to the control Inosine: No major colonies Deoxyadenosine: No major colonies Deoxyinosine: No major colonies

RESULTS

EXPECTED RESULTS The derivatives of the nucleosides will mutate and therefore being carcinogenic.

FUTURE STUDIES Later this summer, we are going to use these compounds to find a cure for viral infections such as the common cold and warts.

REFERENCES Lelie, Van D. “The VITOTOX test, an SOS bioluminescence Salmonella typhimurium test to measure genotoxicity kinetics.” (1997) Ames, Bruce N. “Carcinogens are Mutagens: A Simple Test System Combining Liver Homogenates for Activation and Bacteria for Detection.” 70.8 (1973): McCann, Joyce. “Detection of Carcinogens as Mutagens in the Salmonella/microsome test: Assay of 300 chemicals: Discussion.” Medical Sciences (1976): McCann, Joyce. “Detection of Carcinogens as Mutagens: Bacterial Tester Strains with R Fator Plasmids.” 72.3 (1975):

ACKNOWLEDGEMENTS Special thanks to: Dr. Padmanav Pradhan Dr. Mahesh Lakshman Dr. J. J. Lee Dr. Pallavi Lagisetty Dr. Paul Thomson Dr. Sat Bhattacharya The City College of New York The Harlem Children Society MSKCC