toodle oooo

im just letting you know that i might not post on this blog as often as i may not have internet access in some of the places i go.

im also getting prepared to start my srp as soon as i get back. anyway.. that's all folks.

alrighty fellow srp bloggers.

i believe this is how i shall conduct the experiment:
Soy, full cream and organic milk shall be used.
the different types of milks will be swabbed.
the swabs will be placed in the agar plates.
the bacteria will be allowed to grow for exactly 24x3 hours. that's... 72 hours.
it will be counted and results recorded.
the steps will be repeated 3 or 4 times with one or two day gaps in between the repitition. this is so that i use 2 weeks at least to conduct the experiment. or, maybe just repeat it 3 times and let the bacteria grow for 4 or 5 days?

must research some more >:[

the bacteria in milk pt. 2

• as i have not fully thought about how i will coduct this experiment, i cannot say whether it is 100% reliable. however, what i have thought about now seems to be pretty good. the milks will be swabbed at the same time, twice to make sure that the temperature at which they are swabbed in is the same for both the first and second trials. i don't know whether i should leave them at room temperature or whether i need an incubator.
  
• as mentioned before, the milks will be swabbed twice at the same time (for one type of milk two serial dilutions will be done) to ensure the experiment is fair.
• Yessum, it certainly can be conducted within the time frame. at the very least it will take 2 weeks, to get everything ready and to wait for the bacteria to grow. even if it does take 3 days to grow bacteria, i think i can leave the dilutions in the agar plates for a day or two more :) all together it shold take 3-5 weeks (that's a very rough approximation)
• everything can be conducted at home, home equipment can be used and im not sure about whether to get an incubator or not, still need to think about that. if i do need one i think my parents can get me one :D
• can i give a valid and conclusive result? oh, now there's a question. i haven't done the experiment so i cannot answer that question properly. but i believe that a valid and conclusive response can be drawn from the results of the experiment. Organic milk should have different bacteria quantity to soy milk and skim milk, full cream milk may be similar to skim milk etc.
  

i think im done now.. ok i'll go through everything once more to make sure i have evrything.

bacteria counting

im attempting to watch LOST now, so i'll be brief:
i need different dilutions of my milk samples. this site says that they should be in the quantities of 1:10, 1:100, 1:1000 etc. each dilution is grown in different petri dishes and agar plates.
after 2 or 3 days, the bacteria grows in colonies which appear as small spots on the agar plates. To find out how much bacteria is there i need to count the colonies & by doing this i will know the original amount of bacteria in the milk. so this involves some maths, but i have to research if there are easier ways of doing this or if this is the only one.

blog due tomorrow :/

i'm just checking that i've done everything for tomorrow's blog thing.

• You need to have shown (in your blogs) some ideas which you have researched. At this point, you need to have an initial idea about your experiment and a brief plan as to how you are planning to complete the experimentation. Done.
• 2 marks out of the 15 will be allocated to whether you have sent me a blog URL and whether this was on time. If you were sending it to the wrong address, or something happened with your email, as long as you have shown me the proof that you sent it before it was due, it will not be deemed as late. URL sent :)
• 3 marks of the 15 will be allocated to whether you have been active on your blog. i.e. how much work have you put into posting information onto the blog. oh.. well i hope i have. what can i do now?
• 5 marks will then be allocated to whether you have thought through several different project designs and whether you have listed the independent variable and the dependent variable. i went through around 4 different topics on my blog. i think that's enough. i can't help it if i can't think of original ideas :L
• The last 5 marks will be for whether the experiment:
  1. is reliable
  2. will be conducted fairly
  3. can be completed within the time frame
  4. can be conducted at home using normal household equipment
  5. can give you a VALID and conclusive result. gahhh. not finished. i'll post another blog with this information :)

ok, i guess i better hop to it then. and i have some more research on the milk bacteria counting.

lightbulb

i have new information.

apparently the bacteria in skim milk and full cream milk isnt significantly different, so maybe i should replace one with organic milk? or should i just add organic milk to the list of milks im testing?

and if i don't repeat the experiment at a different time, can i do it twice in one go? like a repetition the same time i do the first one? and do i need an incubator for this or should i leave it at room temperature?

arrgh. so many questions, i'll research this tomorrow.
my shoulders hurt, im off to bed now.
toodle-ooo.

...

i haven't thought much about the srp in the past 24 hours, with the rotation test coming up.. but i think im going to stick with the soy, skim, full cream and long life milk to do my experiment.
im not sure whether to start my experiment now. or when i get back. or maybe i should do one trial of all the milks now and another one when i come back.
my dad (i think) printed this article about the easiest way of counting bacteria, although i haven't gotten around to reading it yet. it looks very helpful, though. i hope they're easy to count. maybe i should read the article. or i'll go to bed and read it in the morning.
yes, i'll go to bed.
good night everyone :]

i've decided not to do any of my srp in India, because there are alot of variables and its not going to be easy. oh, and i have to study for maths and geography as well :( Further investigation shows that it takes way less than 3 weeks for bacteria to grow (thanks ms zhang) and i thought that since it only takes around 3 days, not 3 weeks, i might as well do 3 or 4 different types of milk. so far i've thought about using:

• soy milk
• skim milk
• full cream milk
• long life milk

any other suggestions? or should i stick with these 4?
also, i don't know whether i should actually start doing the experiment now or when i come back. (i come back on april 30th) or should i do half of it before i go and the other half when i get back?
i thought this srp would be so much easier, but there's alot of thought in it... >:[
ok, im going now, i have this science prac report due and man vs wild is on :)

serial dilution

i researched serial dilution, and it basically means diluting a liquid in water or any other solution. That seems to be what i have planned to do for my srp (see previous blog).
I'm still unsure on how to manage the experiment (Ms Zhang- do all the dilutions have to be done at the same time to make it a fair test?) & i still need to work out the variables; so far this is what i have:

• independent variable- the different types of milk
• dependent variable- the amount of different colonies of bacteria
• controlled variable- times that the milk is diluted; no. of days that diluted milk is kept in agar plates.

I also found the 'recipe' or method for making agar plates, it looks really long, though.. i found another site that doesn't involve getting nutrients, but instead using an agar tablet to make it. and i have to make sure i use the EXACT amount of everything when i repeat the experiment. This SRP may take a little longer than i thought to plan.

Ms Zhang- if i make the agar plates myself, would i have to include that in the time of doing my experiment (2wks-6wks)? And the sites, are they the correct methods?

the bacteria in milk

came across an idea to investigate the bacteria in different types of milk.

ok, so maybe around 4 or 5 test tubes/glasses (depending on what i have access to) are gonna be filled with the same amount of water. a swab thing is supposed to be dipped in milk e.g. full cream milk; and then placed in the first glass of water. same thing done with another tube, except after it's dipped in the milk, it gets dipped in the first glass again and then in the second. the third time, the swab gets dipped in the milk, then the first glass, then the second, and finally in the third. same thing for the furth and fifth ones.

Then the swabs are placed on petri dishes (or another alternative) with this nutrient agar thing (google nutrient agar plates, they have a good definition of it). now, im not sure how to do this next part, but somehow the bacteria is counted? i still have to work on that.

The experiment is repeated for skim milk and soy milk. what do you think, good idea? or should i think of another one?

NOTE: my dad said this experiment may take up to 2 weeks, and im going overseas in the holidays, so i was thinking maybe compare soy milk from here and soy milk from india, and skim milk from here and skim milk from india and so on. should i do this or is it too much?

EDIT- it may take up to 3 weeks.