Quantify and measure microplastics simultaneously

I am undertaking microplastic analysis for fibers and fragments that are 280 um and larger. How can I quantify and measure microplastics simultaneously? I have utilized the manual count tool, but I must measure particles prior to counting them. In order to measure, I must delete my manual count points.

Hi Madeline,
Sounds like you are looking for a particle analysis. It all depends a bit on your starting images, but if they can be automatically segmented into individual particles (e.g. by thresholding), the particle analyzer (https://imagej.net/Particle_Analysis; or extended particle analyzer: https://imagej.net/BioVoxxel_Toolbox) should be able to do what you want.
Good luck,

Hi Volko,

Thank you for your response. How do you threshold an image?

This is the point that I’ve gotten to:


Hello Ms. Malloy,
It appears your image is not color so a color threshold would not help much. Using the standard Image> Adjust> Threshold may work a little better. Then when you get what you want, just click the select button at the bottom of the panel. Then you should be able to use Analyze>Analyze Particles. This will give you many different details of your image including counting them.

Hi Bob,

Thank you for your response. My image does contain stains that are colored (red, green, and blue). How would you suggest setting a color threshold to this?


Hello Madeline,
Actually it is difficult to give a good solution without seeing the original image, however you say it has all three channels, have you tried using Image> Color> Split channels. And then only use one channel? For a one channel image you would use Image> Adjust> Threshold which is simpler to understand. There are many ways to accomplish what you wish so a little more detail on what that is would also help.