Science Buddies: "Ask an Expert"

Hi, I am doing a project called "Bioluminescence: Investigating Glow-in-the-Dark Dinoflagellates. For this project, you are supposed to measure the bioluminescence of the Pyrocystis lunula or the Pyrocystis fusiformis. In the procedure, it says to measure the bioluminescence using a scale from 1-4 with 4 being the brightest. I need more quantitative results for my project so I purchased a lux meter. This meter ended up not being able to pick up any of the light coming off of the algae. Is there any solution or other methods to measure the bioluminescence of the algae.

Hi,

I understand your problem with measuring low light intensity such as bioluminescence. Most of the common lux meters are not sensitive enough and ones that are, are very expensive.

The one way that I had thought of, but not tried, was to use a smart phone camera to take a time exposure. Here's a video about how to use a Galaxy8 to take a time exposure, but if you have an i-phone I'm sure there's a video for that:

https://www.youtube.com/watch?v=XdyDDJoDT2A

OK, but now how do you turn a picture into a light measurement? That's where the secret comes in--use a program called ImageJ which is free online: https://imagej.nih.gov/ij/docs/examples/

This program allows you to import a jpg image and measure the pixel density so that you get an actual number.

Try this and let me know how it works out for you. I'm sure you'll have some questions, so post again.

Sybee