Friday, June 24, 2011

Results of my Experiment

I haven't posted in quite a while, because I was organizing all the data and stuff -- there is really quite a lot of data, and I organized them raw data then into groups, for better analysis.

I grouped the bacteria by, as I said, size and colour, but now I encounter quite some difficulty. The first of these is whether I should include analysis of the amount of mould in my report. I recorded the growth of mould in my data because it is very interesting, but it does not really fit my research question which is about bacteria. I think I can change my research to be about 'microbes' but antibacterial hand soap only claims to kill bacteria, so including mould in my research is rather a moot point. 

Another difficulty is the fact that the pH of lime juice and lemon juice is the same - is it because they both contain citric acid? I think it is so, But now, what would be the chemistry aspect of my experiment? I think I will have to analyse the chemical components of the agents and find out what exactly kills or removes bacteria in them -- especially in limes and lemons. If it's really citric acid like I think, then this can be a chemical aspect of the experiment as well. (comparing the chemical properties of substances in removing bacteria).

And finally, I have no idea if we're supposed to hand in a draft of the report upon returning to school? 

Here I am uploading links to the raw and more organized data. 




AND FINALISED DATA OFOR 3RD OBSERVATION FOR ALL BATCHES:

Thursday, June 2, 2011

Experimentation

Have done Day 1 and Day 2 of the experiment. A few corrections to the procedure:
1, used masking tape to seal up plates.
2, did not use stopwatch.

anyway, the results of 1st observation is rather unexpected: a lot of bacteria grew in lemon juice and distilled water, even more than control, while antibacterial soap seem to be nurturing mould.
I'm also having difficulty counting the bacterial colonies. Shall attempt ImageJ again, i took photos of the plates and I have to admit counting them is hard. I'm not sure if I haven't double-counted. And though i classified them into groups based on their sizes, some of them seem to be in between two groups, and some are merging into one (round shape or strip-shape) so it's really hard to count.

That's all for now.