metachromatic body

n.

A concentrated deposit of phosphate polymer, lipid, and nucleoprotein occurring in many bacteria, algae, fungi, and protozoa, and having staining properties different from those of the surrounding protoplasm.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.