Hi! Thanks for helping out

-- I apologize for the large amount of questions that are about to come...I shouldn't have waited until last minute to prepare everything and perhaps not set homework as a solid first priority previously...
I’m facing a bit of a problem in terms of which road to take in a “crossroad” I’m facing. According to the research I have done, it looks like the effectiveness of each method is already very clear, with clear “hierarchies” in terms of accuracy, listing a gfp-biosensor as most accurate, a bioassay as second, and perhaps the TLC as the 3rd.
Also, given some research, it looks like a bioluminence bioassay, for example, detects the presence of A-HL, while TLCs specifically differentiate between the types of A-HL (at least I think this is what my research is trying to say) I’m finishing up my research now, but I’d like to ask:
Since the two methods appear to not compare exactly the same thing, would that be considered another variable? (and therefore it wouldn’t be logical to compare them?) … Also, I’ve done an “originality” check on my experiment – it seems like nobody else has done the comparison before, but I have seen peer-reviewed articles mention the various ways which another method, using an fgp-based biosensor, is more effective than the TLC // I’m not sure what to make of this yet, but I’ll let you know within a few hours

)
As a result,
I am not sure how I can expand on these “accepted” measures of accuracy for the above three types. I was thinking about either 1) continuing on with the topic in ways such as measuring the limitations of each type [as signals include detecting the signals, differentiating between the signals, and detecting/differentiating them in different environments] OR 2) somewhat continue on the topic by attempting to improve a method [I am thinking about the TLC, as it is most accessible]
I have done the preliminary research and know that the materials to prepare a culture (including making the LB, the bacteria).
As for the materials, it looks like we have access to e. coli -- interestingly enough, we have access to genetically modified e. coli with bioluminesence like vibrio strains.
We are also looking to see if we have vibrio bacteria...
Yes, it looks like C. violaceum is out, because in terms of the culture medium I have access to, it’s really only LB.
Here’s my current list of materials:
For the LB media (1 L):
- - 10 g tryptone
- 5 g yeast extract
- 10 g NaCl
- 15 g agar
- Distilled water
- Measuring cylinder (200 ml +)
- Autoclave
- 2 L flask (that can be tightly shut, designed for autoclave)
- Petri dish X 10 (? I know that bacterial strains can easily get infected, but would 10 be enough? (I’m hoping to get more trials for more accurate results)
- Scale boats (weighing) + Scale
- Oven mitts/tongs
- pH strip/meter (detecting appropriate pH for optimal bacterial growth)
- Sodium hydroxide/TRIS for ‘boosting’ Ph
- Bacteria strain [I am checking if I have access to v. fischeri -- if I don't, my backup is e. coli]
- Cotton swabs for inoculation
Materials for the TLC
- Microscopic slides (for the plates)
- Silica (solid absorbent) >> I have yet to ask my teacher if we have these materials, will return with answer within few hours.
- Erlenmeyer flask (for preparation of silica) - 500 ml
- Ethyl acetate
(I’ve seen this being used in many experiments with the TLC, but I am wondering where this would apply?)
Materials for the bioluminesence bioassay
- A CDD Camera (?) for capturing the bioluminesence...
- Not sure yet, more research needed.
In terms of what I know about the TLC, I
do have previous experiments with TLC, but I
do not know what I would be looking for in the TLC plates as it applies to this experiment (hopefully with me finishing reading about the next experiments, I can know. One interesting thing did appear though:
I notice there are experiments that use liquid cultures, and another that use ... solid cultures (perhaps actual agar plates with LB non-liquid media) > in your experience, which one would be more "efficient" in terms of money, preparation time, and accuracy?
Most of the experiments included a similar process as below (this is from
here: )
"The
V. scophthalmi strains A089 and A102 were grown overnight in different growth media (mLB, mTSB, mPW and AB) and the supernatant was analyzed for the presence of AHL-like molecules."
I'm not sure, but is it true that
the analyzing of supernatants is only applicable to liquid cultures? (Since I believe supernatants refers to what remains in a solution after centrifugation...
I'm not 100% sure about whether I'll continue down this road yet, however, I am planning to at least get started by seeing how the TLC works, and possible ways to improve. IF it is not clear that the bioassay/gfp-based biosensor/TLC is more effective than the other two, then I'll continue down this pathway. Though,
may I ask whether these methods are in fact, "comparable" or would it be like comparing an electronic scale to a triple beam balance?
Hopefully the above won't be an issue, as the materials I'm gathering right now can apply to both possibilities (possibility 1) of comparing the methods and 2) of improving a method.
I also have another question though – since I am attempting to detect the signals, I know the composition of the signals I am looking for is OHHL or 3-oxo-C6-HSL (
I believe this is the standard for the A-HL...but I'm not sure what it is O=), but
in terms of “detecting” the actual signal on the TLC, what would I be looking for?
(My teacher also asked me to identify what exactly is the composition of it, and I’m afraid this is a basic concept that is not mentioned in the advanced peer-review articles because it’s very basic =P)
Yes – I did start a bit late <_<. I may have spent too much time brainstorming for a “good” idea, but the good news is, results from bacteria come back fast

.
Update: According to my research, it looks like there are different kinds of bioassay, including a sensor strain bioassay to a TLC bioassay, to a bioluminescene bioassay, all three ideas seem pretty interesting.
In your experience, are the above three methods (of using a sensor strain, using a TLC bioassay and using a bioluminesence assay) "different" enough to compare their effectiveness?
And another update: I am filling out the safety/risk assessment/approval forms right now, so hopefully I can get experiments started soon.
Some
bad news though: I have winter break coming up, which means that I won't have access to materials -- also, my high school science teacher is really nice, helping out with the gathering of the materials

-- I'm afraid I won't really be able to start for another two weeks. >> Is it too late then? (that would leave me with about 2 months of experimentation... 2.5 months at most...)
My plan is to have a research plan developed in these two weeks so that I won't have to stop between experiments, but in an ideal experiment, I learn from my results so that I can shape the future experiments from there. But I do want to apply for the fair this year...(though I plan on making it a 2 year project later) ...
Next time, the TOP thing on my list: START EARLY so I don't have to rush now!
A BIG thank you! (Again, SORRY for the HUGE amount of questions!)