Silver Nanoparticles Microbial Assessment by Adam Yang
Research Silver is considered to be a very toxic and lethal element to many microbes and bacteria. In the last decade, scientist believed that the reason why silver stops bacteria development is because silver breaks chemical bonds therefore stop functions within the cell They believed that the nanoparticles may be absorbed by bacteria and then causing them to burst.
Research -Silver Colloidal Nanoparticles are very tiny (1 nm and 100 nm in size), and consist of a liquid mixture of silver nanoparticles and silver ions. -Found in many common household items.
Research Early scientist realize colloidal silver's anti-bacteria effect so they actually resolve typical illness using this -stress, colds, skin problems, and stomach problems
Research Escherichia coli (E. coli) -very common/popular bacteria, usually found in intestines of organisms -easy to culture, DNA is easily manipulated -E. coli bacteria infection can lead to disruption in the digestive system (ex. Vomitting, stomach aches, diaherrea.
Purpose The purpose of this project was to determine if silver nanoparticles had any significant effect on the growth or development of E.coli.
Hypothesis Null Hypothesis: Silver nanoparticles willl not have any significant effect on the bacteria, E. coli Alternative Hypothesis: Silver nanoparticles have a significant effect on the bacteria, E. coli.
Permanent marker Small mini jars Material Natural Path Silver Wings Dietary Mineral Supplement, colloidal silver, 500 PPM (25 ml) Ethanol Spreader Bar E. coli. Micropipettes Vortex LB media LB petri dishes Microtubes Bunsen Burner Matches
Procedure E. coli was grown overnight in a sterilized lb media A sample of the overnight culture was added to fresh LB media in a sterile sidearm flask. The cultures were incubated at 37 C until a density of 50 Klett spectrophotometer units was reached. These represent cell densities of approximately 108 cells/ml. The cultures were diluted in sterile dilution fluid to a concentration of approximately 103 cells/ml. The culture was placed in an incubator (30 C) until a density of 150 Klett spectrophotometer units was reached. This represents the stock solution of yeast.
Procedure The selected experimental variables were diluted with sterile dilution fluid to the chosen concentrations to a total of 9.9mL 0.1 ml of cell culture was then added to the test tubes, yielding a final volume of 10 ml The solution was mixed by vortexing and allowed to sit at room temperature for 15 minutes After vortexing to evenly suspend cells, 0.1 ml aliquots were removed from the tubes and spread on 56 plates The plates were incubated at 30 C for 24 hours. The resulting colonies were counted. Each colony is assumed to have arisen from one cell.
Concentration Chart Control.001x.01x.1x 1x E. coli 0.1 ml 0.1 ml 0.1 ml 0.1 ml.1ml Sterile Dilution Fluid (SDF) 9.9 ml 9.89 ml 9.8 ml 8.9 ml 8.9mL Collidial Silver nanoparticles 0 ml 0.001 ml 0.01 ml.1 ml 1mL Total Volume 10 ml 10 ml 10 ml 10 ml 10mL
Number of Colonies 160 140 E. Coli survivorship graph P crit.04212 120 100 80 60 40 20 0 Control.001X.01X.1x x Concentrations
Conclusion Since there was a variance in the data shown by the evidence of p <.05, the null is rejected. Therefore silver does have a microbial affect on E. coli. Even though the null was rejected, there showed miminum actual variances in different results.
Future Considerations Variables needed to be changed through the experiment was plating was not synchronized. Use different model instead of E. coli to test the if Silver antiparticles didn't just have a effect on a the bacteria, E.coli. Test more concentrations Use pure silver nanoparticles instead of a mixture of ions and particles.
Worksite/ References http://www.webmd.com/a-to-z-guides/e-coliinfection-topic-overview http://www.sigmaaldrich.com/materialsscience/nanomaterials/silvernanoparticles.html http://www.sigmaaldrich.com/materialsscience/nanomaterials/silvernanoparticles.html