Dinoflagellate Bioluminescence

[Michaela_Prasad]

Hi, I am doing a project about dinoflagellates. I found a photometer that measures lux (0-50,000) on Amazon. I wanted to know if this tool would be able to measure the amount of bioluminescence dinoflagellates produce. Thank you!!!

[deleted-71536]

Hi Michaela,

It sounds like you are interested in doing a project like this one: https://www.sciencebuddies.org/science- ... p033.shtml. In this project, you can make your own brightness scale to measure the differences in bioluminescence (which doesn't cost any money!). If you are interested in increasing your precision and accuracy, then you could use a photometer to measure the light given off by your dinoflagellates.

I hope this helps. Please post again (in this same thread) if you have more questions.

Heather

[Michaela_Prasad]

Hi Heather, thank you so much for replying. I plan on using a photometer that reaches 50,000 lux. I was also wondering how much lux should be directly put on them? I read somewhere that said there should be 7,000 lux, but that seemed kind of high. When I tried putting a lamp above them it reached about 250 lux. What would a good amount be?Thank you!

[deleted-71536]

Hi Michaela,

The procedure calls for a fluorescent bulb, which would probably get no higher than 500 lux maximally. (See the Wikipedia article about lux for some estimates: http://en.wikipedia.org/wiki/Lux.) I do not know where you read that you should put 7,000 lux directly on them, but that seems too high to me, too. Ultimately what matters is that you are consistent. If your lamp gives off in the range of 250 lux, that seems completely reasonable.

Since you've measured your lamp, keep in mind that your dinoflagellates are not likely to give off light at an intensity (much) higher than the light put on them, so you'll need to set your photometer to read in the range of 0-250 lux. If you try to set the range for over 1,000 lux, the photometer may not pick up the light.

I hope that helps! Please keep me posted on your progress.

Heather

[Michaela_Prasad]

Heather,
Thank you that helps a lot!!! I am so sorry I have to keep bothering you with questions. I was wondering what I could do that would keep the dinoflagellates flashing long enough to get a lux reading? Would a magnetic stir plate work well for this? That has been a problem for me. Thank you so much!!!

[deleted-71536]

Hi Michaela,

You could try a magnetic stirrer, but that requires putting a magnet in your dinoflagellate culture. If you do decide to go that route, make sure you always use the exact same stir setting (speed), so that you are agitating each culture by the same amount. Another option would be to see if you can find a culture lab with a large (non-magnetic) stir plate used for overnight bacterial cultures. I am talking about a device with a platform that moves in a circular motion. You could place your dinoflagellate culture tubes onto the platform (in a rack, for example), and the rotation of the platform will agitate your cultures.

Either way, I think you are on the right track. Let me know if you still have questions.

Best,
Heather

[Michaela_Prasad]

Thank you so much!!! You have helped me so much. I ended up getting the magnetic stir plate, and have been measuring it at the same speed. I have been using a multimeter connected to an ultra sensitive light sensor to read the bioluminescence. I also have put in the environmental pollutants I planned on using. I have a kind of odd question to ask you about a pollutant I used. I put in a rusted screw about 2 centimeters long in a beaker of 50 mL of dinoflagellates. I took out the screw when I mixed it with the stir plate. The odd thing was, when I mixed, the dinoglagellates glowed very bright, but the multimeter didn't sense it at all. Do you think it is possible that the dinoflagellates got a magnetic charge, and that is why the multimeter didn't sense them? I tried mixing it again today, and the multimeter still didn't pick it up. Sorry this question is so weird!!!
Michaela

[deleted-71536]

Hi Michaela,

That is a weird result! I don't think that a magnetic charge should affect your readings, especially since you have been using a magnetic stir plate for your other readings. Have you checked that your multimeter is set to the right range? If your dinoflagellates were glowing extra bright, it is possible that the readings were higher than the set range on your multimeter. That's the only explanation I can think of, based on what you described.

Heather

[Michaela_Prasad]

Heather,
I tried what you said and I still couldn't get it to work. Thank you for the suggestion though.
I still haven't been able to get a reading on that. I have another questions for you (sorry!!!) I was
wondering if dinoflagellates used Binary Fission or Mitosis to reproduce. I know that they mainly reproduce
asexually but I dont know how. Thanks!!!
-Michaela

[deleted-71536]

Hi Michaela,

This may be why the instructions called for you to use a scale of brightness (1 to 5) that you set yourself, so you can describe how brightly they were bioluminescing. Did you use that scale in addition to the multimeter readings? If so, you still have data you can use. If not, you can try that instead.

Dinoflagellates are protists, which are eukaryotic cells (have a true nucleus). All eukaryotic cells use mitosis to divide. Only prokaryotes (bacteria) use binary fission.

I hope that helps. Please keep me posted on your progress!

Heather

[Michaela_Prasad]

Dear Heather,
I can not thank you enough! You have helped me so much. I was able to find a way to determine brightness. Thank you for your suggestions, they have helped me work through this whole project. My project is coming along very well thanks to your help. It is due Wednesday and I am almost finished completely. Thanks again!
-Michaela
P.S. Thanks for explaining to me the Binary Fission/ Mitosis question

[deleted-71536]

I'm glad to help, and very happy to hear that your project is going well and almost complete! Great job.

[conordumbrell]

Hi Michaela,
I'm thinking of doing my IB Extended Essay on this and have been wondering if you got any readings with a lux photometer as I'm concerned mine won't be precise enough. What kind of lux values did you receive with your set up?
Any help would be much appreciated.