Dinoflagellate Experiment?

[deleted-358122]

For my Internal Assessment, I'm measuring how salinity affects the intensity of dinoflagellates' glow. First of all, if I have them in 10 mL water, can I just add 1 g of salt to create 10% salinity, since water has a 1ml/1g density? When I did it, it seemed like way too much salt. Secondly, can I use a lux meter to measure the intensity of their luminescence? I was told to just tap them and measure the duration of their "flash" but I think that's too subjective.
Thanks,
Abby

[deleted-291782]

Hi Abby,

In the lab, we will often measure a solute concentration as a percentage expressed as mass per volume. So, to create a 10% saline solution, you could add 1 gram of salt to 10 mL of water. However, this is likely too much salt as you noted. You could try a few different amounts of salt; physiological saline solutions are 0.9%, so you could try a few around this range.

To answer your second question, you could use an instrument to measure the luminescence. However, I would be sure that you are consistent as to where you measure this in each of your samples in order to maintain consistency. I agree that sometimes the readout could be viewed as too subjective, unless there are clear differences in the luminescence when you conduct your experiment. If this is the case, simply giving your own rating will be sufficient.

Let us know if you have further questions. Good luck!

-Pharma