I finally finished my report!!! it is a really great and rather difficult experience to put all my thoughts and results down, as there are so much to write about!! but at last, it is done and I have said all that I want to.
Here are the links to the online files mentioned in my Appendix:
RAW DATA: https://spreadsheets.google.com/spreadsheet/ccc?key=0AiMAlvdzOfXFdEYyQ1doTmctZzJkaFV2aHU3LW5xUVE&hl=en_US#gid=0
Secondary data: https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0ByMAlvdzOfXFYzU0NGI5YjItYWE2OC00ZTcwLWFkNDUtYmIwZTI5N2MzMmEw&hl=en_US
Tertiary data: https://spreadsheets0.google.com/spreadsheet/ccc?key=0AiMAlvdzOfXFdEM1UWY0Rm1paXNLZ1RweS01SU1uYmc&hl=en_US
Photographs: https://picasaweb.google.com/108870368937199680879/SIPDataPhotosUploaded
To the dear teachers marking this blog and the report: I know I've put up links to my data in the previous posts, but these are the refined ones, so they would be slightly different and more organised.
My blog has been a faithful documentation of the thought processes in planning the experiment, and notes taken to refine the report, etc etc. Thank you blog!
Monday, July 25, 2011
Thursday, July 14, 2011
Notes about my experiment and report
We went through the rubrics today. Things to note:
1. Present representative photographs in appendix, and add a link in the hardcopy to the online scrapbook to see full details of photos.
2. MUST paraphrase the lit review presented in the report. Would there be a section in template to include lit review?
3. Refer to lit review in the design of the experiment
4. For results, use 2 decimal places of accuracy whenever unsure. Follow strictly the calculation of levels of precision as learnt in physics.
5. Methodology MUST be reproducible - ask friend to try out based on given instructions.
6. Point out control variables that cannot be controlled.
7. Remember to vary ONLY ONE variable.
8. Data collection: is all the data collected necessary? Are the data collected enough for a good graph/analysis?
9. Presentation of data - in tables, with appropriate and SPECIFIC units and precision.
10. plot a graph for data analysis, in my case the rate of bacteria growth as graphs.
11. Use line graphs for rates and bar graphs for numbers.
12. refer back to literature review and observations in conclusion.
13. Limitations - things that you really cannot control about the experiment.
14. Extension - VERY IMPORTANT. further questions from your experiment. Crucial in a scientific investigation.
15. Provide plenty of evidence - hard data and photos - in the blog.
16. List out materials specifically.
17. Reflect on how to make the experiment better with more time/how to make it bigger.
1. Present representative photographs in appendix, and add a link in the hardcopy to the online scrapbook to see full details of photos.
2. MUST paraphrase the lit review presented in the report. Would there be a section in template to include lit review?
3. Refer to lit review in the design of the experiment
4. For results, use 2 decimal places of accuracy whenever unsure. Follow strictly the calculation of levels of precision as learnt in physics.
5. Methodology MUST be reproducible - ask friend to try out based on given instructions.
6. Point out control variables that cannot be controlled.
7. Remember to vary ONLY ONE variable.
8. Data collection: is all the data collected necessary? Are the data collected enough for a good graph/analysis?
9. Presentation of data - in tables, with appropriate and SPECIFIC units and precision.
10. plot a graph for data analysis, in my case the rate of bacteria growth as graphs.
11. Use line graphs for rates and bar graphs for numbers.
12. refer back to literature review and observations in conclusion.
13. Limitations - things that you really cannot control about the experiment.
14. Extension - VERY IMPORTANT. further questions from your experiment. Crucial in a scientific investigation.
15. Provide plenty of evidence - hard data and photos - in the blog.
16. List out materials specifically.
17. Reflect on how to make the experiment better with more time/how to make it bigger.
Friday, July 8, 2011
Review and Revise
After meeting Ms Tan, I need to do another batch of bacteria culture as I did not have negative control (an agar plate that has absolutely nothing done to it, to see the sterility of the agar plates), so in this new batch there will be a 7th plate, the negative control. I also need another batch to consolidate the results I have which are right now rather messy. If i have another set of results, I can analyse it more and perhaps identify the outliers more easily.
Another matter I am considering is the method of presenting my data. After all, I really have a lot of data. Right now I'm presenting in a table and maybe graphs the average amount of each type of bacteria on agar inoculated by each agent ON THE 3RD DAY, and on the 3rd day only. I have not yet decided whether to use the data of Days 1 and 2 anywhere. I think I need to decide because if not, I can save work and time by not counting the bacteria on Days 1 and 2 for my 4th batch.
I'm thinking to not waste any data, and present data about the rate with which DIFFERENT TYPES OF BACTERIA appear on plates inoculated with DIFFERENT AGENTS. to this, i can plot a combined graph of each type of bacteria, x-axis the number of days, y-axis the amount of bacteria, different lines representing different agents. Or I can plot combined graphs of each type of agent, with the same axes, the different lines representing the different types of bacteria. It all seems very very complicated.
So should I present the rate at which bacteria appear? It promises to be interesting, but is it relevant to my research question which is about the amount of bacteria removed? Does the rate at which bacteria colonies grow have any significance on the amount of bacteria inoculated onto the plate?
Or - another idea - maybe i can just use the data from Day 1, immediately after inoculation and on 3rd day.
Ms Tan also advise me to:
1, use pi to calculate area
2, use imageJ?
3, think about whether using different fingers affect the amount of bacteria
4, THE OPAQUE WHITE 'MOULD' IS ACTUALLY BACTERIA.
5, use the great photos i have so painstakingly taken!! yay, should i attached ALL of them as appendix?
By the way, is there a limit for appendix pages?
Another matter I am considering is the method of presenting my data. After all, I really have a lot of data. Right now I'm presenting in a table and maybe graphs the average amount of each type of bacteria on agar inoculated by each agent ON THE 3RD DAY, and on the 3rd day only. I have not yet decided whether to use the data of Days 1 and 2 anywhere. I think I need to decide because if not, I can save work and time by not counting the bacteria on Days 1 and 2 for my 4th batch.
I'm thinking to not waste any data, and present data about the rate with which DIFFERENT TYPES OF BACTERIA appear on plates inoculated with DIFFERENT AGENTS. to this, i can plot a combined graph of each type of bacteria, x-axis the number of days, y-axis the amount of bacteria, different lines representing different agents. Or I can plot combined graphs of each type of agent, with the same axes, the different lines representing the different types of bacteria. It all seems very very complicated.
So should I present the rate at which bacteria appear? It promises to be interesting, but is it relevant to my research question which is about the amount of bacteria removed? Does the rate at which bacteria colonies grow have any significance on the amount of bacteria inoculated onto the plate?
Or - another idea - maybe i can just use the data from Day 1, immediately after inoculation and on 3rd day.
Ms Tan also advise me to:
1, use pi to calculate area
2, use imageJ?
3, think about whether using different fingers affect the amount of bacteria
4, THE OPAQUE WHITE 'MOULD' IS ACTUALLY BACTERIA.
5, use the great photos i have so painstakingly taken!! yay, should i attached ALL of them as appendix?
By the way, is there a limit for appendix pages?
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.
ORGANIZED DATA: https://docs.google.com/document/d/1ZnpbuhF-Avogif4IaRSYlt47SR_Yf7IYIZqX4irqQRw/edit?hl=en_US
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.
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.
Sunday, May 29, 2011
Final Experiment Procedure
After the many changes my experimental plan has gone through, I come up with this final procedure.
Materials and Apparatus:
18 prepared agar petri dishes
20 ml of pure lime juice
20 ml of pure lemon juiceDistilled water
20 ml of normal hand soap (brand: )
20 ml of antibacterial hand soap that claims to kill 99.9% of bacteria (Dettol brand)
5 sterilized falcon tubes
1 10 ml syringe without needle
1 timer
Tap waterScotch tape
Pre-experimental preparations:
1, squeeze pure lime juice from Small Limes bought from supermarket, into 1 labeled falcon tube.
2, squeeze pure lemon juice from Green Seedless Lemon bought from supermarket, into 1 labeled falcon tube.
3, squeeze normal hand soap and antibacterial hand soap into respective labeled falcon tubes.
4, test the pH of lime juice and lemon juice for data analysis to see which contains more citric acid.
5, prepare sufficient distilled water obtained from school lab into 1 labeled falcon tube.
6, cleanse the syringe with distilled water.
7, rinse right thumb and index finger under tap water.
Procedure:
(Day 1)
1, Prepare 6 lidded agar plates.
2, Inoculate 1 agar plate with the uncleaned left thumb by streaking in a systematic, even, S shaped pattern across the agar. Use the entire finger and not just the finger tip. Lid and label the plate.
3, Clean the left index finger with lime juice. Use the syringe to extract 5ml of lime juice from the falcon tube and pour evenly onto the finger. Scrub evenly and firmly with right thumb and index finger 10 strokes. Let the lime juice stay on the finger for another 10 seconds. Rinse finger under running water for 10 seconds.
4, Repeat Step 2 with the cleaned left index finger.
5, Cleanse the syringe with distilled water and right thumb and index finger under tap water.
6, Clean the left middle finger with lemon juice by repeating Step 3.
7, Repeat Step 2 with the cleaned left middle finger.
8, Repeat step 5.
9, Clean the left ring finger with normal (BRAND) hand soap by repeating step 3.
Materials and Apparatus:
18 prepared agar petri dishes
20 ml of pure lime juice
20 ml of pure lemon juiceDistilled water
20 ml of normal hand soap (brand: )
20 ml of antibacterial hand soap that claims to kill 99.9% of bacteria (Dettol brand)
5 sterilized falcon tubes
1 10 ml syringe without needle
1 timer
Tap waterScotch tape
Pre-experimental preparations:
1, squeeze pure lime juice from Small Limes bought from supermarket, into 1 labeled falcon tube.
2, squeeze pure lemon juice from Green Seedless Lemon bought from supermarket, into 1 labeled falcon tube.
3, squeeze normal hand soap and antibacterial hand soap into respective labeled falcon tubes.
4, test the pH of lime juice and lemon juice for data analysis to see which contains more citric acid.
5, prepare sufficient distilled water obtained from school lab into 1 labeled falcon tube.
6, cleanse the syringe with distilled water.
7, rinse right thumb and index finger under tap water.
Procedure:
(Day 1)
1, Prepare 6 lidded agar plates.
2, Inoculate 1 agar plate with the uncleaned left thumb by streaking in a systematic, even, S shaped pattern across the agar. Use the entire finger and not just the finger tip. Lid and label the plate.
3, Clean the left index finger with lime juice. Use the syringe to extract 5ml of lime juice from the falcon tube and pour evenly onto the finger. Scrub evenly and firmly with right thumb and index finger 10 strokes. Let the lime juice stay on the finger for another 10 seconds. Rinse finger under running water for 10 seconds.
4, Repeat Step 2 with the cleaned left index finger.
5, Cleanse the syringe with distilled water and right thumb and index finger under tap water.
6, Clean the left middle finger with lemon juice by repeating Step 3.
7, Repeat Step 2 with the cleaned left middle finger.
8, Repeat step 5.
9, Clean the left ring finger with normal (BRAND) hand soap by repeating step 3.
10, Repeat Step 2 with the cleaned left ring finger.
11, Repeat step 5.
12, Clean the left little finger with Dettol antibacterial hand soap by repeating Step 3.
13, Repeat Step 2 with the cleaned left little finger.
14, Repeat step 5.
15, Clean the right middle finger with distilled water by repeating Step 3.
16, Repeat Step 2 with the cleaned right middle finger.
17, Seal all agar plates with Scotch tape and leave for 24 hours in a warm location of about 28 degrees C, out of direct sunlight.
(Day 2)
18, Repeat Steps 1-17 with another 6 agar plates, using control on RMF, lime juice on LT, lemon juice on LIF, normal hand soap on LMF, antibacterial soap on LRF, distilled water on LLF.
19, Observe the first 6 plates from Day 1. Record the amount of bacteria growth by organizing the bacteria colonies using a chart of various bacteria colony sizes and counting the number of colonies. Also record the different types of bacteria that grow. Take photographs.
(Day 3)
20, Repeat steps 1-17 with another 6 plates, using control on LLF, lime juice on RMF, lemon juice on LT, normal hand soap on LIF, antibacterial hand soap on LMF, distilled water on LRF.
21, Observe bacteria growth on the plates from Days 1 and 2.
(Day 4)
22, Repeat step 19 on plates from Days 1, 2, and 3.
(Day 5)
23, Repeat step 19 on plates from Days 2 and 3.
(Day 6)
24, repeat step 19 on plate from Day 3.
25, Organize the data, compare from different plates and analyse.
Friday, May 27, 2011
More research on agar and bacteria culture
General information about agar:
1, Chemically, agar is a polymer made up of subunits of the sugar galactose, and is a component of the cell walls of several species of red algae that are usually harvested in eastern Asia and California.
2, Agar's chief use is as a culture medium for various microorganisms, particularly for bacteria
3, Agar is preferred over regular gelatin for culturing bacteria because agar will not be degraded (eaten) by bacteria. Also, it is firmer and stronger than gelatin.
" For students growing bacteria at home without the supervision of a teacher (for example, investigating bacteria growth at various places around the house), it's important to use an agar formulation that does not preferentially grow one kind of bacteria over another. The worst case would be one that preferentially grew pathogenic bacteria. Therefore, we recommend a plain nutrient agar, of which LB agar is a subtype.There are many different suppliers for LB agar. Because some suppliers will not sell to students directly, you may have to have your teacher order for you. If you are doing a project that involves inoculation and plate streaking, we highly recommend conducting the experiment at a school lab under teacher supervision. "Preparing bottled agar and plates
Although pre-poured agar plates are available, one can make agar plates from tablet, powdered, or bottled agar by following a few simple instructions. Agar kits usually come with detailed instructions on how to prepare plates, and below are sample procedures for reference. When in doubt, be sure to clearly read the instructions and ask for help if needed (either consult a teacher or call the technical help line of the agar kit supplier).
I think I will be using bottled agar or, if possible, pre-poured plates:
"Preparing Bottled Agar:
- Loosen the bottle cap, but do not remove the cap while heating.
- Warm the agar bottle in a hot water bath or in the microwave until it becomes liquid.
- After opening the cap, pass the neck of the agar bottle through a flame to sterilize it. Do not lose the cap!
- While pouring the agar, open the Petri dish lid as little as possible, hold it at an angle, and make sure the lid is kept directly over the Petri dish.
- Pour enough melted agar into each sterile plastic Petri dish to cover 1/8" of the bottom. Cover the lid of the Petri dish immediately.
- Place agar plates on a counter top to cool and set. Agar medium will set like stiff gelatin at room temperature.
- Pass the neck of the agar bottle through flame again before applying the cap.
Preparing Pre-Poured Plates: If plates have been refrigerated, set them out and allow them to warm to room temperature.
Storage: Stack agar plates upside down in the refrigerator. Do Not Freeze! The purpose of placing the plates upside down is to prevent condensation from dripping down onto the agar surface which could then facilitate movement of organisms between colonies.
About the incubator:
I will ask my Mother to take my plates to her lab for incubation and will proceed with observations at her lab. So the incubator is settled.
About the transfer of bacteria by contact:
"
1. Prepared petri dishes should be refrigerated until used and always stored upside down (i.e media in upper dish, cover on bottom). This keeps condensation which forms in the lid from dropping onto and disrupting the bacteria growing surface.
2. When ready to use, let dishes come to room temperature before taking samples (about one hour).
3. Without tearing the agar surface, inoculate the dish by gently pressing fingers, finger nails, coin, etc onto agar surface. (Direct contact of lips or tongue is NOT a good idea.)
4. Replace cover on dish, tape closed, and label each dish so you know the source of the bacteria. Store upside down.
5. Let grow in undisturbed warm location, ideally in an environment around 100° F (37° C) - not in sunlight or on a heating register.
6. You should see growth within a couple of days. The dishes will start to smell which means the bacteria are growing.
7. Make observations and keep records of what you see growing in each dish. Can you make any conclusions about what objects had the most bacteria?
8. Before disposing of dishes in the trash the bacteria should be destroyed. Pour a small amount of household bleach over the colonies while holding dish over sink. Caution - do not allow bleach to touch your skin, eyes or clothes. It will burn!"
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