Are responsible for recycling matter back into the food web once an organism has died

Decomposers.

Explanation:

Decomposers break down dead matter to recycle it back into the ecosystem. Have you ever seen mushrooms on a dead log? They're there because they are breaking down the dead matter, which gets recycled back into the Earth.

Hope this helps! :)

this protocol describes a detailed procedure for intracellular flow cytometry staining.